the 2001 interactive regional highway atlas – …...the 2001 interactive regional highway atlas...

Working Paper 05-05

The 2001 Interactive Regional Highway Atlas – Processing Excel and Access Files

By Jon Hallas Data Analyst

July, 2005 Chicago Area Transportation Study

300 W. Adams St., Chicago, Illinois 60606

The 2001 Interactive Regional Highway Atlas –

Processing Excel and Access Files

By Jon Hallas Data Analyst

July, 2005

Chicago Area Transportation Study 300 W. Adams St. Chicago, IL 60606

The 2001 Interactive Regional Highway Atlas – Processing Excel and Access Files

Abstract

CATS is preparing a series of working papers documenting creation of the 2001 Interactive Regional Highway Atlas. The spreadsheets and database are the Average Annual Daily Traffic (AADT) estimates displayed in the atlas. This working paper includes the following major content items:

Steps toward updating spreadsheets for individual facilities and summary spreadsheets for the expressway/toll highway system in northeastern Illinois

Rationale for converting spreadsheets to database format Issues unique to the database Making spreadsheet data compatible for exporting by the database Updating the data dictionary and table design Describing the unique ID scheme for records Importing spreadsheets into the database Updating the master database table Documenting progress CD containing spreadsheets, database and appendices

The working papers will explain the major processes involved in updating the atlas. Topics under consideration are listed below.

Updating the Map Book Updating Spreadsheets and VMT Database Geodatabase and SDE ArcIMS

Visit the CATS website, www.catsmpo.com, for links to the 2001 Interactive Regional Highway Atlas, links to the handbook series and to contact us with questions about the atlas.

TABLE OF CONTENTS PREFACE ....................................................................................................................... v I. Background ............................................................................................................ 1 II. Annual spreadsheet updates for individual facilities................................................. 3 III. Updating original spreadsheets (‘long’ format) ......................................................... 4 IV. Verifying data ......................................................................................................... 7 V. Updating summary data spreadsheets..................................................................... 8 VI. Why convert data from Excel format to Access format?......................................... 11 VII. Choosing unique ID's and data at expressway and toll highway junctions............. 12 VIII. Interchange segments without data ....................................................................... 13 IX. Modifying Excel spreadsheets to convert data to .mdb format............................... 15 X. Reducing spreadsheet size ................................................................................. 21 XI. Updating the data dictionary............................................................................... 22 XII. Updating .mdb table design ................................................................................ 23 XIII. Importing spreadsheets in Access ......................................................................... 24 XIV. Replacing null values .......................................................................................... 27 XV. Updating the master .mdb table (tblAll_records) .................................................... 32 XVI. Conclusion ........................................................................................................... 38 TABLE OF FIGURES Figure 1. Comparing original and modified format spreadsheets .................................... 3 Figure 2. Cells from previous year to be copied .............................................................. 4 Figure 3. Copy, paste new formatted cells ...................................................................... 5 Figure 4. Update column headings ................................................................................. 6 Figure 5. Spreadsheet filled with new AADT data ........................................................... 6 Figure 6. Summary sheet with VMT totals for each facility in each direction................... 8 Figure 7. Summary sheet with summed bidirectional VMT ............................................. 9 Figure 8. Summary data for the Elgin-O'Hare Expressway Westbound .......................... 9 Figure 9. Elgin O'Hare expressway data linked to the summary table .......................... 10 Figure 10. Spreadsheet modified .................................................................................. 15 Figure 11. Columns formatted for new data .................................................................. 16 Figure 12. Updated column headings are copied and pasted in place.......................... 17 Figure 13. Data from the long format spreadsheet are pasted ...................................... 18 Figure 14. Note the 2nd row of pasted data has been changed .................................... 19 Figure 15. The placement of all data have been adjusted............................................. 19 Figure 16. Data are copied and pasted to the final location .......................................... 20 Figure 17. Spreadsheet with only the essential data to be imported by Access............ 21 Figure 18. Fields to be added to update the Data Dictionary ........................................ 22 Figure 19. Table "All_records" in design view. .............................................................. 23

Figure 20. Activating the Import feature in Access ........................................................ 24 Figure 21. Select the file to be imported........................................................................ 24 Figure 22. Message In Import Spreadsheet Wizard ...................................................... 25 Figure 23. Replacing null values, choosing selected fields. .......................................... 28 Figure 24. Query revealing cells with null values .......................................................... 28 Figure 25. Update Query, Part 1 ................................................................................... 29 Figure 26. Update query, Part 2 .................................................................................... 29 Figure 27. Update query, Part 3 .................................................................................... 30 Figure 28. Update query, Part 4 ................................................................................... 30 Figure 29. Update query, Part 5 .................................................................................... 31 Figure 30. Updating the master table, create a new query............................................ 32 Figure 31. Selecting tables............................................................................................ 32 Figure 32. Joining tables ............................................................................................... 33 Figure 33. Fields to be updated are chosen .................................................................. 34 Figure 34. Query type changed from Select to Update ................................................. 34 Figure 35. Open Expression Builder.............................................................................. 35 Figure 36. Use an expression to update values ............................................................ 35 Figure 37. Results of the completed expression .......................................................... 36 Figure 38. Completed Update query ............................................................................. 36 Figure 39. Table All_records with updated records ....................................................... 37 APPENDICES Appendix I ..................................................................................................................... 39 Appendix II .................................................................................................................... 41 Appendix III ................................................................................................................... 43 Appendix IV................................................................................................................... 45 Appendix V.................................................................................................................... 49

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PREFACE

A series of working papers is being written explaining how to recreate the 2001 Interactive Regional Highway Atlas. Key building blocks used to create the atlas will be discussed in separate working papers. Each part of the process will be put in context and steps needed to update the project will be identified. The series of working papers will be written for persons who already have a basic working knowledge of spreadsheet, database or ArcGIS programs. It will not be geared to persons looking for introductory texts about the capabilities of software programs or for instructions about how to use the software. Providing advanced technical documentation is not the goal of the working papers, although some detailed instructions are included. This working paper includes the following major content items: Steps toward updating spreadsheets for individual facilities and summary

spreadsheets for the expressway/toll highway system in northeastern Illinois Rationale for converting spreadsheets to database format Issues unique to the database Making spreadsheet data compatible for importing into the database Updating the data dictionary and table design Describing the unique ID scheme for records Importing spreadsheets into the database Updating the master database table Documenting progress CD containing spreadsheets, database, and appendices

Presenting technical documentation in a series of papers instead of a single volume has three advantages. First, the process of updating the whole 2001 Interactive Regional Highway Atlas is more easily understood as a series of manageable parts. Each volume will provide practical information about a major stage of the update and also step-by-step instructions on performing the update. Finally, the series should be completed and available to users more quickly than would a single large publication. A number of topics are under consideration as potential working papers: 1. Updating the Map Book 2. Updating Spreadsheets and VMT Database 3. Geodatabase and SDE 4. ArcIMS

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I. Background Annual AADT/VMT reports began for the year 1995, although reports have been published periodically since 1965. The annual reports are issued because the data play a significant role in obtaining Federal Highway Administration (FHWA) funds for Illinois. The Chicago region, located within IDOT District 1, includes a large share of the state’s FHWA appropriation. The format and appearance of the AADT/VMT reports have changed due to software updates and to the desire to make data more widely available. The changes are listed below. - Data for 1995-1997 were prepared using Lotus123 5.x for Windows 3.1; - Data were converted to .xls format when the agency began using Excel

spreadsheets programs exclusively. Data for 1995-1999 were converted to and processed using Excel 97;

- Other upgrades to the spreadsheet format have included Excel 2000 and Excel 2003;

- Spreadsheets for 1995-2001 data were converted to .mdb (Access) format; - Beginning with data for 2003, AADT and VMT have been reported in both .xls

and .mdb formats. Conversion to .mdb is necessary because the default database for ArcGIS and ArcIMS is .mdb format (Access). Although spreadsheets are not easily accepted by ArcGIS and ArcIMS, they are easily adapted or converted to .mdb format. This working paper documents the process of converting data from Excel (.xls) spreadsheet to Access (.mdb) database format.

The 1995 Travel Atlas illustrates the expressways and toll highways, along with AADT for each highway segment and ramp, in northeastern Illinois. Using the 1995 Travel Atlas to process AADT makes traffic flow easier to understand. After CATS obtained licenses for ArcGIS and ArcIMS (Internet mapping), creating an updated version of the Atlas for the Internet became a possibility. An Internet version of the Atlas has these advantages: - Fulfill the annual requirement to report data for FHWA funding requests; - Make AADT/VMT data available to a much wider audience through the Internet; - Allow atlases to be updated more quickly and more often. This working paper identifies steps that were taken to update spreadsheets and the database for 2002 data with 2003 data. Users will need to create and manage new files for subsequent years. The updating process can be complex and confusing, so it is recommended that users update one facility in one direction at a time. For example, update the Elgin-O’Hare expressway, eastbound, steps III. through XV, then update the Elgin-O-Hare expressway, westbound. Users may also wish to ease into the process by starting with facilities with a smaller number of records, like the Elgin-O-Hare expressway or Lake Shore Drive, before taking on larger facilities.

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Spreadsheets, database and appendices are provided on a companion CD.

A number of working papers document the technical aspects of balancing AADT, explain how VMT are calculated, show how to understand AADT traffic flow, and give overviews of the 2001 Interactive Regional Highway Atlas. Refer to Appendix I, Further Reference for a list of these documents.

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II. Annual spreadsheet updates for individual facilities

Spreadsheets for individual facilities by direction are currently in the two formats listed below. A. Original format spreadsheets based on the first annual report prepared for 1995

data. Data for each record is contained on two rows with AADT and VMT calculations occurring on the 2nd row.

B. Modified format spreadsheets that can be easily imported using Access. Modified format spreadsheets are based on the original format spreadsheets. The major difference is that data for each record is contained on a single row.

Figure 1. Comparing original and modified format spreadsheets

(Note that throughout this paper that within the graphic, the width of some columns has been shrunk and some columns have been hidden to save space.)

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III. Updating original spreadsheets (‘long’ format) A. Use ‘long’ format original spreadsheets from

2002_long_format/year_facility_direction as parent files for year 2003 working copies. Copy them to a new folder, for example, 2003_long_format/year_facility_dir. Update the file titles, for example, from 02_Edens_EB to 03_Edens_EB. See CD for sample files.

B. Keep track of progress using a spreadsheet updating chart. Refer to Appendix II Spreadsheet Update Tracking Chart, for a suggested initial layout. A copy also resides on the accompanying CD.

C. Follow these steps while in the ‘long’ form spreadsheet (e.g., 2003_long_format / 03_Edens_EB).

1. Highlight and Edit, Copy the cells for 10 columns for the previous year (year 2002, BF4 . . . BO4).

Figure 2. Cells from previous year to be copied

2. Position the cursor to create new formatted cells, then Edit, Copy,

Paste Special, Format. In this example the cursor location is cell BQ4. Adjust the width of spacing columns (columns shaded gray) to 1 character.

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Figure 3. Copy, paste new formatted cells

3. Delete columns related to ’95-02 change and update new column

headings for 20031

1 Directional designations were changed in the 2003 AADT/VMT report from inbound or outbound to northbound, southbound, eastbound or westbound. For example, the Edens Expressway is designated as either eastbound or westbound for spreadsheets with data beginning in year 2002. Spreadsheets created for data between 1995 and 2001 use inbound or outbound directional references. A chart cross-referencing both naming conventions is found in Appendix III, “Changes In Direction Designations”, and on the CD.

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Figure 4. Update column headings

4. Enter data for year 2003

Figure 5. Spreadsheet filled with new AADT data

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IV. Verifying data Checking and verifying data and saving files are strongly suggested throughout the process of updating and converting data. Use total AADT or VMT and the number of records as controls for each facility in each direction. Updated AADT and VMT are established at the completion of Section III Updating original spreadsheets (‘long’ format). The number of records for a facility will not change unless an interchange has been reconfigured. Compare these data after the following major phases have been completed.

- Section VIII, Modifying Excel spreadsheets to convert data to .mdb format - Section IX, Reducing spreadsheet size - Section XII, Importing spreadsheets in Access - Section XIV, Updating the master .mdb table (tblAll_records)

Keep track of verifying data using a spreadsheet updating chart. Refer to Appendix II, Spreadsheet Update Tracking Chart, for a suggested initial layout. The CD also includes a copy.

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V. Updating summary data spreadsheets Summary data spreadsheets include total AADT from individual facilities. (Refer to 2003_long_format/2003_vmt_summaries_to_IDOT.xlw.) The sheet titled “By_direction” contains annual VMT totals for each facility in each direction and also includes number and percent changes in VMT during the period 1995-2003.

Figure 6. Summary sheet with VMT totals for each facility in each direction. Annual number and percentage changes and for 1995-2003 also appear.

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A. The sheet titled ‘Sum_2003’ includes similar statistical comparisons for summed bidirectional VMT for each facility and for the expressway and toll highway system as a whole.

Figure 7. Summary sheet with summed bidirectional VMT for each facility

and for the entire expressway and toll highway system

B. Follow the steps below to update the summary spreadsheets ‘By-direction’ and ‘Sum_2003’. - Select the summary data found at the bottom of five columns, ‘2003 VMT’,

‘02-03 Changes – Diff. and %’, and ’95-0 Changes – Diff. and %’,

Figure 8. Summary data for the Elgin-O'Hare Expressway Westbound to be linked to summary spreadsheets for the expressway-toll highway system

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- In the Edit menu, click Copy - In the expressway-toll highway summary spreadsheet, sheet ‘By_direction’,

select the corresponding five cells for the Elgin O’Hare Expressway Westbound, [(‘2003 VMT’, ‘Difference (03-02)’, ‘Percent’, ‘Difference (03-95)’, and ‘Percent’].

- In the Edit menu click Paste Special, then click Paste Link.

Figure 9. Elgin O'Hare expressway data linked to the summary table

- After data has been linked from Elgin O’Hare Expressway Eastbound, calculate the bidirectional sum and differences found in row 22 in the above example.

- Copy and link the bidirectional data to the appropriate cells in summary data sheet ‘Sum_2003’.

- In both summary data sheets, select the cells containing the linked data. - In the Edit menu, click Copy, then click Paste Special, then click Values.

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VI. Why convert data from Excel format to Access format? Spreadsheet (.xls) data for AADT and VMT had to be converted to database (.mdb) format because ArcIMS does not readily accept .xls files. The default format for personal geodatabases in ArcView, ArcInfo and ArcIMS software is .mdb format. Fortunately, data in our spreadsheets could be modified to a format that could be successfully imported by Access. Details are provided in Section IX, Modifying Excel spreadsheets to convert data to .mdb format.

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VII. Choosing unique IDs and data at expressway and toll highway junctions

Ramps at expressway/toll highway interchanges often have dual functions. An expressway off-ramp, for example, may also function as an on-ramp for an intersecting toll highway. Estimated AADT are provided from both possible sources, from IDOT and also from ISTHA. As a result, the subject ramp has two possible unique identifying numbers and two different AADT values. Geographic information systems, however, will accept only one identifying number, so only one ID number, with its corresponding AADT value, can be chosen for the attribute. In cases where toll highways intersect expressways, the estimated AADT value from ISTHA and its corresponding identifying number take precedence over the estimated AADT value from IDOT and its accompanying identifying number. The system created for establishing unique identification numbers is found at Appendix IV, Atlas 2003 Unique ID Numbering Scheme, and on the CD.

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VIII. Interchange segments without data Segments connecting expressways and toll highways sometimes do not have surveillance. Examples are the connectors between the East-West Toll Highway and the North-South Toll Highway, or the junction of the Tri-State Toll Highway, the Northwest Toll Highway and the Kennedy Expressway. CATS only reports estimated AADT/VMT; however, that can be supported through electronic surveillance. When segments without surveillance are selected in the Interactive Regional Highway Atlas the message ‘There is no data for this segment’ appears.

Segments without data were given unique identifying numbers corresponding to the Unique ID Numbering Scheme (such at 14400 and 14500) so they could be included in the Interactive Regional Highway Atlas. Refer to Appendix IV, Atlas 2003 Unique ID Numbering Scheme for the complete list of connectors without reported data.

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IX. Modifying Excel spreadsheets to convert data to .mdb format

A. Data for individual records occupies two adjacent rows in the existing spreadsheets. In a personal database, data for individual records must be included within a single row.2

B. Use spreadsheets from the directory 2002_1row_format as parent files for 2003 data. These spreadsheets have already been modified to include all data for a record on a single row. The naming format is year_facilityname_direction(2). An example would be 02_Edens_EB(2).

C. Copy files to a new folder, such as 2003_1row_format/ year_facilityname_direction(2), and update the year from 02 to 03. Take the steps below to update them with 2003 data.

D. Open the spreadsheet [(2003_1row_format / 03_Edens_EB(2).

Figure 10. Spreadsheet modified so that all data for a record is contained in a single row

2 Each record must have a unique identifying number, so a unique ID numbering scheme was devised by assigning numbers in series of 100s for each of the spreadsheets organized by facility and by direction. For example, records for the Dan Ryan Westbound Local were sorted in ascending order, then assigned unique IDs between 1 and 99. Records for the Dan Ryan Eastbound Local were given IDs between 101 and 199 in the same manner, and those for the Dan Ryan Westbound Express were assigned IDs between 201 and 299. The complete unique IDs scheme can be found at Appendix IV, Atlas 2003 Unique ID Numbering Scheme.

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E. Highlight the five columns for a single year of data. In this case the year is 2001,

but any year would be OK. Select column headings 2001, 2001_off, 2001_on, 2001_Mainline and 2001_VMT, and continue down to the last row with data. In the Edit menu, click Copy,

F. Position the cursor to create newly formatted columns, (in this case cell AV1). In

the Edit menu, click Copy, then click Paste Special, then click Formats. The result will be formatted, yet blank cells.

Figure 11. Columns formatted for new data

G. Select column headings 2001, 2001_off, 2001_on, 2001_Mainline and 2001_VMT.

H. In the Edit menu, click Copy. I. Position the cursor at the first row of newly formatted columns (cell AV1), then in

the Edit menu click Paste. J. Update the columns for the current year (2003).

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Figure 12. Updated column headings are copied and pasted in place

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K. Fill all cells in column 2003 with ‘2003’. L. From the original long format spreadsheet (e.g., 2003_long_format/

03_Edens_EB), select all the 2003 data from columns “Off”, “On”, “Mainline,” and “VMT”.

M. In the Edit menu, click Copy. N. Open the appropriate corresponding file (e.g., 2003_1row_format/

03_Edens_EB(2) and position the cursor below the columns just formatted, then in the Edit menu, click Paste Special, then click Values.

Figure 13. Data from the long format spreadsheet are pasted below

the formatted columns

O. Data just copied needs to be edited so that all information for a record exists on a single row. In the Edit menu, use Cut and Paste operations, and also select and Delete empty rows so that the ramp, mainline and VMT data for each record is contained in a single row.

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Figure 14. Note the 2nd row of pasted data has been changed so all the data for the record is on a single row

Figure 15. The placement of all data have been adjusted so data for one record is within a single row

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P. After editing has been completed, select all the edited data. In the Edit menu, click Copy,

Q. Position the cursor immediately under the column heading “2003_Off’ (cell AV2 in the figure below).

R. In the Edit menu, click Paste Special, then click Values.

Figure 16. Data are copied and pasted to the final location in the modified spreadsheet

S. Delete data located below the formatted spreadsheet. T. In the File menu, click Save.

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X. Reducing spreadsheet size A. Reducing the spreadsheet size offers these advantages:

1. Reduces the number of steps in importing data 2. Decreases the likelihood of error 3. Makes proofreading and quality checking easier 4. Saves storage space

Use the following steps to edit the spreadsheet to include only the essential data needed to update the database. B. Create a new file folder for spreadsheets to be imported by Access, for example,

2003_ss_for_import. Copy the newly created file (such as 2003_1row_format/ 03_Edens_EB(2) to this folder and give it a distinguishing filename (for example 03_Edens_EB(2)_edit).

C. Delete all fields except those listed below. The resulting spreadsheet (with only 6 remaining fields) will be imported by Access: 1. ID 2. 2003 3. 2003_Off 4. 2003_On 5. 2003_Mainline 6. 2003_VMT

D. Retain column headings in the first row to facilitate quality checking as data are being imported.

Figure 17. Spreadsheet with only the essential data to be imported by Access

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XI. Updating the data dictionary The data dictionary defines fields and their characteristics in the database. The data dictionary needs to be updated to include five new fields for 2003 data: the year of the data, estimated AADT for off-ramps, AADT for on-ramps, AADT for mainlines, and VMT. These added fields are shown in the figure that follows. View the full data dictionary in Appendix V, Data Dictionary for the 2003 Atlas or refer to the copy in the CD.

Figure 18. Fields to be added to update the Data Dictionary

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XII. Updating .mdb table design A. The existing table (“All_records”) in file Atlas2003.mdb must be updated to

accept 2003 data. Use the following steps. (A copy of the database resides on the CD.) 1. Add new fields (“Field Name”) for 2003 data to the main table using the data

dictionary as a guide. 2. Adjust Data Types and Field Properties according to the data dictionary.

Figure 19. Table "All_records" in design view

(Note new fields have been added for 2003 data)

Note the master database table design needs to be updated only once at the beginning of the update process to accommodate the new fields.

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XIII. Importing spreadsheets in Access A. In Access, open the database (Atlas2003.mdb). B. In the Objects column, right click Tables, then click Import.

Figure 20. Activating the Import feature in Access

C. In the Import window, Files of type, click Microsoft Excel (.xls). D. Navigate to and click the specially formatted .xls file, the current example being

2003_ss_for_import / 03_Edens_EB(2)_edit. Click Import.

Figure 21. Select the file to be imported

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E. Because column titles are present, you may get a message from the Import Spreadsheet Wizard regarding data in the first row that cannot be used for field names. If such a message appears, disregard it and click Next.

Figure 22. Message In Import Spreadsheet Wizard

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F. The Import Spreadsheet Wizard will appear. Follow the directions below to advance the importing process. 1. Check the First Row Contains Column Headings box, then click Next. 2. Under Where would you like to store your data?, click the radio button In a

New Table, then click Next. 3. Under Field Options, match the following entries:

- Field Name ID - Indexed, Yes (No duplicates) - Do not import field (Skip) should remain unchecked - Click Next.

4. Select Choose my own primary key. In the adjacent text box, enter ID. Click Next.

5. In the text box immediately beneath Import to table:, name the new table, giving it a name that’s easy to remember, (e.g., Edens_EB_edit).

6. Click Finish. 7. A message will appear - ‘Error in creating primary key on field ‘ID’. Don’t

worry about it - click OK and continue. 8. A message should appear stating that the data has been successfully

imported into a new table. G. Open the table and check for the correct number of records and for complete

data throughout the table. In this case, use table 03_Edens_EB(2)edit for the comparison. Check especially for the following conditions: 1. Extraneous fields added during the importing process. Delete any extra fields. 2. Extraneous rows added during the importing process. Delete any extra rows. 3. Null or blank cells should only occur in the 2003_Off and 2003_On fields. If

null cells are present elsewhere, check the spreadsheets for errors, make corrections and start the importing process again.

4. Save the corrected table. H. Also examine the table in Design View. Compare the table with the Data

Dictionary to find discrepancies. Look especially carefully at the data type column and field properties because corrections are usually needed in both these places. If a message appears stating that changes may result in losing some data, click OK and continue.

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XIV. Replacing null values A. All cells in the final form of the database should contain a value – none should be

null, blank or empty. Inspect the imported table again and note the fields where blank cells exist. Replace the null values with 0 by creating and running Update queries. Follow the steps below.3

B. In the Objects column click Queries, then double click Create query by using wizard. (Note the wizard creates Select queries.)

C. In the Tables/Queries drop-down box of the Simple Query Wizard window, select the newly created table (in this example tblEdens_EB_edit).

D. In the Available Fields box, move these fields to the Selected Fields box, then click Next. 1. ID 2. 2003_Off 3. 2003_On

3Why not use Replace in the Edit menu to fill blank cells in spreadsheets before they are imported? Experience has shown that the import process accepts the 0s only part of the time, so filling blank cells in spreadsheets isn’t a reliable way to deal with the issue of ensuring that each cell contains a value. Using Update queries to fill null cells has been found to be a consistently successful method for solving the problem.

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Figure 23. Replacing null values, choosing selected fields.

E. Click Finish. The query will automatically open. Notice the cells with null values.

Figure 24. Query revealing cells with null values

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F. Open the new query in Design view, click the Query Type icon and choose Update Query.

Figure 25. Update Query, Part 1

G. In the Criteria row of field 2003_Off enter Is Null. H. In the Update To row of field 2003_Off enter “0” (zero with surrounding

quotation marks).


I. In the Query menu, click Run. J. A message will ask if you want to update the records. Click Yes. K. Minimize the window.

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L. Open updated tblEdens_EB_edit to view the results. Notice in field 2003_Off the null cells have been updated with 0s.


M. Minimize tblEdens_EB_edit. N. Maximize the Update query in Design view. O. Delete the previous entries in field 2003_Off. P. In the Criteria row of field 2003_On, enter Is Null. Q. In the Update To row of field 2003_On, enter “0” (zero surrounded by quotation

marks).


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R. In the Query menu, click Run. S. A message will ask if you want to update the records. Click Yes. T. Close the window, then save the update query. U. Open updated tblEdens_EB_edit to view the results. Notice in field “2003_On”

the null cells have been updated with 0s. In fact, no null cells should be remaining in this table.

V. The process of replacing null values in this table is complete.


W. Close and save both the query and table.

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XV. Updating the master .mdb table (tblAll_records) New tables with updated data by facility and by direction will be used to update the master table. Follow these steps in the updating process: A. In the Objects column, click Queries, then double click Create query in design

view.

Figure 30. Updating the master table, creating a new query

B. In the Show Table frame, select the master table All_records and the newly created table (for example Edens_EB_edit).

Figure 31. Selecting tables

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C. Close the Show Table frame. D. Join the ID fields from both tables by clicking field ID in tblAll_records and

dragging to field ID in tbl_Edens_EB_edit. A line connecting the ID fields will appear.

E. Right click on the connecting line. In the text box that appears, select Join Properties. The Join Properties frame will appear. Verify that the correct tables and columns are shown in the drop-down boxes.

F. Select Option 1: Only include rows where the joined fields from both tables are equal. Click OK.

Figure 32. Joining tables

G. In the upper pane, in tblAll_records, double click on the fields listed below. The fields will appear in the lower pane after each selection has been made. 1. ID 2. 2003 3. 2003_Off 4. 2003_On 5. 2003_Mainline 6. 2003_VMT.

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Figure 33. Fields to be updated are chosen

H. Use the Query Type icon to change from Select Query to Update Query.

Figure 34. Query type changed from Select to Update

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I. In the Update To row in field 2003, click the Expression Builder icon. The Expression Builder frame will appear.

Figure 35. Open Expression Builder

J. Create an expression to update Field 2003 with corresponding values from the imported table, in this case tblEdens_EB_edit, Field 2003.

Figure 36. Use an expression to update values

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K. Click OK. The expression appears in row labeled Update To:

Figure 37. Results of the completed expression

L. Create similar expressions to update fields in tblAll_records with data from tbl Edens_EB_edit. Remaining fields to be updated are listed below. 1. 2003_Off 2. 2003_On 3. 2003_Mainline 4. 2003_VMT. The following figure shows the completed Update query.

Figure 38. Completed Update query

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M. In the Query menu, click Run. A cautionary message will appear asking if the update should continue. If the number of rows to be updated is correct, and you are confident that the expressions are correct, click Yes. Consider having a spare copy of the database ready to use in case the update query is not successful and the process needs to be attempted again.

N. Save and close the update query. O. Open tblAll_records to review the records for complete and accurate updated

data.

Figure 39. Table All_records with updated records

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XVI. Conclusion The update process needs to be followed as described beginning in “II. Annual Spreadsheets Updates For Individual Facilities” for all 38 facilities in the expressway/toll highway system.

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Appendix I Further References Below is a listing of working papers produced by CATS about the VMT database along with content highlights for each paper. All volumes are available in .pdf format from the publications section of the CATS website, www.catsmpo.com. CATS Working Paper 97-19: VMT Data Base, Northeastern Illinois Expressway and Tollway Systems

Description of methodology used and variables included in the spreadsheets Hard copies of the database (spreadsheets) including AADT and VMT for the

expressway and tollway system for years 1995 and 1996. CATS Working Paper 00-05: VMT Database Update To 1999, Northeastern Illinois Expressway And Tollway Systems

Database (spreadsheet) structure and variables Summary sheets of annual total VMT for 1995-1999 by facility by direction,

annual percentage change, percentage change for the period 1995-1999 Hard copy of detailed 1995-1999 AADT for each facility by direction

CATS Working Paper 01-13: Northeastern Illinois Expressway System Atlas, Annual Average Daily Traffic Volume Balancing Technical Process and Methodology

Sources of data and formats in which it is received Methodology for balancing data from different sources Overview of how the database is used by CATS and other agencies

CATS Working Paper 04-03: Moving the Regional Highway Atlas to the Internet: A Technical Overview

Rationale for making the 2001 Atlas available on the Internet Geography and attributes Atlas network and attribute development software Atlas Internet application development software Implementation

CATS Working Paper 04-04: Dealing with AADT and VMT Data in the 2001 Interactive Regional Highway Atlas

Comparison of 1995 Atlas (hard copy) and the 2001 Interactive Atlas (Internet application)

General description of converting data from spreadsheet (.xls) format to database (.mbd) format

Thumbnail sketch of digitizing and editing shapefiles

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Appendix II Spreadsheet Update Tracking Chart

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Appendix III Changes In Direction Designations Changes In Direction Designations For Expressways and Toll Highways Effective for the 2003 AADT and VMT Report Former designations (Inbound or Outbound) were changed to Eastbound (EB), Westbound (WB), Northbound (NB), or Southbound (SB) Former New Former New Designation Designation Designation Designation Dan Ryan IL-53 Inbound WB Inbound SB Outbound EB Outbound NB Dan Ryan Express Kennedy Inbound WB Inbound EB Outbound EB Outbound WB Edens Kennedy Reversible Inbound EB Inbound EB Outbound WB Outbound WB Edens Spur Kingery Inbound EB Inbound WB Outbound WB Outbound EB Eisenhower Lake Shore Drive- N Inbound EB Inbound SB Outbound WB Outbound NB Elgin O'Hare Lake Shore Drive- S Inbound EB Inbound NB Outbound WB Outbound SB East-West Tollway Northwest Tollway Inbound EB Inbound EB Outbound WB Outbound WB Ford Freeway North-South Tollway Inbound WB Inbound NB Outbound EB Outbound SB I-290 Stevenson Inbound EB Inbound NB Outbound WB Outbound SB I-57 Tri-State Tollway Inbound NB Inbound EB

Outbound SB Outbound WB

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Appendix IV Atlas 2003 Unique Id Numbering Scheme

2003 Atlas Unique Id Numbering Scheme Highway Direction Records w/Data Records w/o Data Name New Old Operation Id Series # Records Id Series # Records Dan Ryan WB IB Local 1 42 10000 1 Dan Ryan EB OB Local 101 42 10100 1 Dan Ryan WB IB Express 201 6 10200 1 Dan Ryan EB OB Express 301 6 10300 1 Edens EB IB Local 401 33 10400 1 Edens WB OB Local 501 33 10500 1 Eisenhower EB IB Local 601 43 10600 1 Eisenhower WB OB Local 701 43 10700 1 Elgin-O’Hare EB IB Local 801 10 10800 1 Elgin-O’Hare WB OB Local 901 10 10900 1 Ford WB IB Local 1001 26 11000 1 Ford EB OB Local 1101 26 11100 1 Kennedy EB IB Local 1201 69 11200 1 Kennedy WB OB Local 1301 66 11300 1 Kennedy EB IB Reversible 1401 6 11400 1 Kennedy WB OB Reversible 1501 7 11500 1 Kingery WB IB Local 1601 9 11600 1 Kingery EB OB Local 1701 9 11700 1 Lake Shore Drive –North SB IB Local 1801 23 11800 1 Lake Shore Drive –North NB OB Local 1901 25 11900 1 Lake Shore Drive – South NB IB Local 2001 10 12000 1 Lake Shore Drive – South SB OB Local 2101 12 12100 1

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2003 Atlas Unique Id Numbering Scheme Highway Direction Records w/Data Records w/o Data Name New Old Operation Id Series # Records Id Series # Records Stevenson NB IB Local 2201 52 12200 1 Stevenson SB OB Local 2301 52 12300 1 Ill .Rt. 53 SB IB Local 2401 17 12400 1 Ill .Rt. 53 NB OB Local 2501 17 12500 1 I-57 NB IB Local 2601 23 12600 1 I-57 SB OB Local 2701 23 12700 1 I-290 Extension EB IB Local 2801 30 12800 1 I-290 Extension WB OB Local 2901 32 12900 1 East-West Toll Highway EB IB Local 3001 34 13000 1 East-West Toll Highway WB OB Local 3101 33 13100 1 Northwest Toll Highway EB IB Local 3201 33 13200 1 Northwest Toll Highway WB OB Local 3301 32 13300 1 North-South Toll Highway NB IB Local 3401 24 13400 1 North-South Toll Highway SB OB Local 3501 25 13500 1 Tri-State Toll Highway EB IB Local 3601 72 13600 1 Tri-State Toll Highway WB OB Local 3701 71 13700 1 Edens Spur EB IB Local 3801 3 13800 1 Edens Spur WB OB Local 3901 3 13900 1

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2003 Atlas Unique Id Numbering Scheme Highway Direction Records w/Data Records w/o Data Name New Old Operation Id Series # Records Id Series # Records I-290 Ext NS Toll Highway Connector n/a IB Local 14000 1 I-290 Ext NS Toll Highway Connector n/a OB Local 14100 1 EW NW Toll Highways Connector EB IB Local 14200 1 EW NW Toll Highways Connector WB OB Local 14300 1 TriState Kennedy NWToll Connector EB IB Local 14400 1 TriState Kennedy NWToll Connector WB OB Local 14500 1 TriState I-290 EW Toll Connector EB IB Local 14600 1 TriState I-290 EW Toll Connector WB OB Local 14700 1 Chicago Skyway WB IB Local 14800 1 Chicago Skyway EB OB Local 14900 1 I-80 EB IB Local 15000 1 I-80 WB OB Local 15100 1 I-90 IN WB IB Local 15200 1 I-90 IN EB OB Local 15300 1 I-94 IN WB IB Local 15400 1 I-94 IN EB OB Local 15500 1 1,132 56 Total 1,188

Appendix V Data Dictionary For 2003 Atlas Database

Data Field Decimal Field Name Type Size Places Index Description

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Id Number Integer 0 Yes, but Unique record numbers within range assigned by highway, direction & No Duplicates operation Highway_name Text 255 na na Name of the expressway or tollway generally associated with the facility

but not necessarily the full or complete name. Direction Text 255 na na Direction of travel; EB = eastbound, WB = westbound, NB = northbound and SB = Southbound. Expressways and toll highways in northeastern Illinois can be associated with a general directional bearing of either toward or away from the Chicago Central Business District (CBD). Route_Number Text 255 na na Interstate, State or Local route number for the facility Extent Text 255 na na Approximate endpoints of the highway within IDOT District I with surveillance Data_source Text 255 na na Primary data source as found in 1995 Atlas Operation Text 255 na na Mode of operation as indicated by L=Local, E=Express, R=Reversible Location Text 255 na na Name of the entry or exit points along the highway. The location or ramp name corresponds to the street served by the ramp. MP_Start Number Double 2 Yes, but Milepost identifying the location of the ramp activity at the beginning Duplicates OK point of the segment. These data were taken from the Illinois Department of Transportation (IDOT) Illinois Roadway Information System (IRIS). The source data from IRIS was current to 1993. As a result, not all the

ramps could be identified in the database. Estimated values can be found in the spreadsheets in bold Italics typeface.

MP_End Number Double 2 Yes, but Milepost identifying the location of the end point of a segment. These Duplicates OK data were taken from the Illinois Department of Transportation (IDOT) Illinois Roadway Information System (IRIS). The source data from IRIS was current to 1993. As a result, not all the ramps could be identified in the database. Estimated values can be found in the spreadsheets in bold Italics typeface.

Data Dictionary For 2003 Atlas Database


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Distance Number Double 2 Yes, but Distance of segment calculated by (MP_End) – (MP_Start) Duplicates OK 1995 Number Integer 0 Yes, but Identifies that subsequent columns will include data for 1995. Duplicates OK 1995_Off Number Double 0 No The number of vehicles getting off a facility at a particular ramp in 1995

on a typical day. The value is expressed as AADT. Source data for expressways came primarily from a loop detection system maintained by IDOT. Source data for tollways were developed by the Illinois State Toll Highway Authority (ISTHA). See 1995 Travel Atlas Chicago Area Transportation Study, 1998, for a synopsis of the traffic counting processes form which the AADT's were derived.

1995_On Number Double 0 No The number of vehicles getting on a facility at a particular ramp on a typical day in 1995 expressed as AADT. 1995_Mainline Number Double 0 No The number of vehicles traveling on the segment expressed as AADT. 1995_VMT Number Double 0 No Vehicle Miles Traveled for 1995 on a particular segment. VMT values

were derived by multiplying mainline AADT's by the distance of the respective segments. Values were rounded to the nearest whole unit.

1996 Number Integer 0 Yes, but Identifies that subsequent columns will include data for 1996. Duplicates OK 1996_Off Number Double 0 No The number of vehicles getting off a facility at a particular ramp in 1996


1996_On Number Double 0 No The number of vehicles getting on a facility at a particular ramp on a typical day in 1996 expressed as AADT.



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1996_Mainline Number Double 0 No The number of vehicles traveling on the segment expressed as AADT. 1996_VMT Number Double 0 No Vehicle Miles Traveled for 1996 on a particular segment. VMT values

Were derived by multiplying mainline AADT's by the distance of the respective segments. Values were rounded to the nearest whole unit.


On a typical day. The value is expressed as AADT. Source data for expressways came primarily from a loop detection system maintained by IDOT. Source data for tollways were developed by the Illinois State Toll Highway Authority (ISTHA). See 1995 Travel Atlas Chicago Area Transportation Study, 1998, for a synopsis of the traffic counting processes form which the AADT's were derived.







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1998_On Number Double 0 No The number of vehicles getting on a facility at a particular ramp on a Typical day in 1998 expressed as AADT. 1998_Mainline Number Double 0 No The number of vehicles traveling on the segment expressed as AADT. 1998_VMT Number Double 0 No Vehicle Miles Traveled for 1998 on a particular segment. VMT values



on a typical day. The value is expressed as AADT. Source data for expressways came primarily from a loop detection system maintained by IDOT. Source data for tollways were developed by the Illinois State Toll Highway Authority (ISTHA). See 1995 Travel Atlas Chicago Area Transportation S7tudy, 1998, for a synopsis of the traffic counting processes form which the AADT's were derived.


Were derived by multiplying mainline AADT's by the distance of the respective segments. Values were rounded to the nearest whole unit.

2000 Number Integer 0 Yes, but Identifies that subsequent columns will include data for 2000. Duplicates OK



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2000_Off Number Double 0 No The number of vehicles getting off a facility at a particular ramp in 2000










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2003_On Number Double 0 No The number of vehicles getting on a facility at a particular ramp on a typical day in 2003 expressed as AADT. 2003_Mainline Number Double 0 No The number of vehicles traveling on the segment expressed as AADT.



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2003_VMT Number Double 0 No Vehicle Miles Traveled for 2003 on a particular segment. VMT values


Date_Open Number Integer 0 Yes, but Year any portion of the expressway or toll highway was first open. Does Duplicates OK not indicate subsequent construction or year construction of the whole facility was completed.

the 2001 interactive regional highway atlas – …...the 2001 interactive regional highway atlas...

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