CITY WATCH 15SUNDAY TRIBUNE JUNE 21 2015

THE Council for Scien-tific and IndustrialResearch has pub-lished a comprehen-

sive technical guide on pot-holes which addresses suchquestions as what causes themand how they can be repaired.It also highlights how to pre-vent them.

The guide says the numberof potholes in South Africanroads in the past few years hasincreased considerably, leadingto serious concern.

This can be attributed pri-marily to reduced preventativemaintenance on many roads,combined with particularlywet periods during rainy sea-sons and rapidly increasingnumbers of heavy vehicles.

It says that, while there isno doubt that water is the pri-mary cause of potholes, theingress of water into the roadstructure to cause the potholesis mostly due to the conditionof the road surface.

A lack of periodic and/orpreventative maintenance,such as crack-sealing to pre-vent water getting into theunderlying road layers, leads toweaknesses developing in theroad pavement structure.

This results in even morecracks that allow rapid accessof water to the structural lay-ers of the road.

With constrained roadbudgets, preventative mainte-

nance is often reduced ordelayed. This significantlyincreases the potential for thedevelopment of potholes dur-ing wet weather.

The main technique forreducing pothole formation istimeous maintenance at theappropriate standard.

The guide lists other causesof potholes.

Less frequently, they havenon-structural origins such asdiesel or other chemical spil-lages, mechanical damage toroad surfaces from vehiclerims, as well as accidents andfires.

Damage can also be causedby falling rocks in cuttings,animal hooves on the road sur-face in hot weather, and poorroad design.

Most potholes are caused by environmental conditions,water in the road pavementstructure, and tyre loads.

Water on the road will sel-dom be the sole cause of pot-holes, nor will traffic on a dry,well-maintained road.

Only a combination of traf-fic and wet or poorly main-tained roads, will produce pot-holes.

When a bituminous (black-top) road is constructed, thesurface consists primarily of acombination of bitumen andcrushed stone.

Bitumen is a unique mate-rial that bonds crushed stone

together or to the surface ofthe underlying road layer.

The properties of bitumenchange with hot and cold tem-peratures. This allows it to beflexible enough to absorb thesmall strains (movements) thatoccur at the surface of the roadwhen traffic passes over it,without cracking in typicalroad operating temperatures.

Over time, the bitumen“dries out” and becomesharder and less flexible. This isknown as ageing, which is aresult of, for instance, long-

term exposure of bitumen toultraviolet radiation.

As this happens, the cumu-lative movements of the roadsurface result in a fatiguing ofthe bitumen which eventuallycracks. This can be likened tothe repeated bending of a pieceof wire until it breaks.

Only by applying a newbitumen seal or rejuvenatingthe existing bitumen can thefatigue be avoided.

A new bitumen seal obvi-ously returns the road surfaceto a high degree of flexibility

(with some improvement inriding quality). But it is expen-sive, costing between R15 andR38 a square metre.

The use of rejuvenators, atabout R5 a square metre, pro-vides temporary relief by soft-ening dry bitumen and makingit more flexible for a limitedtime – about two or three years.

All roads under traffic andenvironmental conditions willeventually crack. All roadsdeform slightly when a heavyvehicle passes over them.Should the surfacing have

dried out with time (as is thecase with most South Africanroads), this repeated deforma-tion results in cracking.

The increasing number ofheavy vehicles on rural roadsis also accelerating the rate ofdeterioration of these roads.

When potholes are notrepaired timeously, they deteri-orate rapidly and becomelarger and deeper, until patch-ing maintenance is no longerpossible.

Expensive reconstruction isthen necessary.

CHARMEL PAYET

THE purpose of the city’s Engi-neering Unit is to provide engi-neering, building and builtenvironment infrastructure, aswell as surveying and landinformation services to resi-dents, businesses and councilmanagement. It is also taskedwith delivering outputs thatmeet the social and economicneeds of its stakeholders.

There are seven depart-ments that fall under the unit:● Roads Provision● Development Engineering● Infrastructure Managementand Socio-Economic Develop-ment● Surveying and Land Infor-mation● Architecture● Coastal, Stormwater andCatchment Management● Roads and Stormwater Main-tenance

Roads and StormwaterMaintenance deals with repair-ing potholes and maintainingroads.

The Engineering Unit isheaded by Greg Evans. Each ofthe departments has its ownhead. Below is a brief overviewof each department and itsmain functions.

Dave ThomasDeputy head of Roads ProvisionThis division carries out thedetailed design and construc-

tion of capital roads projects,civil engineering structures,the major rehabilitation ofroads, pavement-design testingand pavement management.

Chris HardyDeputy head of Roads DevelopmentEngineeringThis department does designand construction of engineer-ing capital projects on behalf ofother departments, includingurban renewal and economicdevelopment projects.

David LievaartActing deputy head of InfrastructureManagement and Socio-EconomicDevelopment

This department co-ordinatesthe implementation of assetmanagement in the city by de-fining infrastructure assetrequirements, developing andimproving life-cycle infrastruc-ture asset management strate-gies, and integrating, develop-ing and improving infra-structure assets.

Alan ChristisonDeputy head of Surveying and LandInformationThis department providesland-usage surveys, an engi-neering and sectional-title sur-veying service, as well asadvice on land legal and techni-cal issues and land acquisition.

Functions include facilitat-ing land acquisition, land-planpreparation and land-develop-ment plans, land surveying,engineering and sectional-titlesurveying, land legal and landtechnical advice, capital proj-ect land acquisition, planpreparation and land develop-ment, plan and documentmicrofilming and services, andretirement certificates relatingto municipal business.

Nina SaundersActing deputy head of ArchitectureThis department provides professional services in archi-tecture, project management,urban design, landscape archi-

tecture, quantity surveying,structural engineering,mechanical and electrical engi-neering, and building mainte-nance.

Functions include provid-ing professional advice to thecity manager and council,design, managing the develop-ment and construction of allarchitectural and relatedmunicipal projects and provid-ing maintenance services forcouncil buildings and propertyassets.

Randeer KasserchunDeputy head of Coastal Stormwaterand Catchment ManagementThis department’s duty is to

provide a cost-effective, envi-ronmentally sympathetic andsustainable coastal stormwa-ter and catchment manage-ment system.

Functions include manag-ing flood risks, striving toimprove water quality in thecity’s rivers and wetlands, pro-tecting and enhancing urbanriver corridors and wetlands asimportant natural landscapeswithin the urban landscape,and maintaining a suitablebeach width.

Ken HobsonDeputy head of Roads andStormwater MaintenanceThis department operates from25 depots in six regions withineThekwini.

Functions include routineinspection of the road andstormwater network; repairsto sinkholes, potholes and roadsubsidences; repairs/reinstate-ments of excavations, trenchesand localised failures on roadsand pavements; repairs, main-tenance and unblocking thestormwater drainage systems;replacing missing covers,access lids and bollards; andrepairs/replacements of guardrails, roadside fencing and traf-fic lines and signs. Its is alsoinvolved with stream cleaningand maintenance, removal ofrubble and sand from roads,and upgrading low-volumegravel roads.

Before and after pictures of Wood Road, Montclair, after maintenance work was done by the eThekwini Municipality’s Roads ProvisionDepartment. Picture: SUPPLIED

THE length of the road network in the eThekwini municipal areais 9 462km. Roads are maintained by the following authorities:

●The SA National Roads Authority Limited, responsible formaintaining the N2 and N3 freeways, totalling about 367km.

●The KwaZulu-Natal Department of Transport, which looksafter provincial roads. Numbers are prefixed by the letters “M”,“P” or “R”. For example, M19, M7, M4, P100 and R102. Contactthe department at 031 469 8900 to report complaints about theseroads.

●The eThekwini Roads and Stormwater MaintenanceDepartment, responsible for maintaining a network of roadstotalling 7 682km.The unit also maintains about 1 420km of gravelroads. In addition, there are about 110 000 inlets and manholes inthe municipal stormwater system maintained by the department.An average of approximately 1 000 covers are lost annually owingto theft and damage.

The M4 South in Durban is one of a number of roadsmaintained by the KZN Department of Transport. Mostprovincial roads are prefixed by the letters ‘M’,‘P’ or ‘R’.

Picture:TERRY HAYWOOD

CHARMEL PAYETdrives the

pothole campaign

Holestoryof SA’sroads

Teams tasked with maintaining Durban’s infrastructure

Water, heavy vehicles and poormaintenance, are largely toblame for the deterioration,writes Charmel Payet

REPORT POTHOLES

MAKING COMPLAINT CALLS

READERS’ POTHOLE GRIPES

THE city’s engineering call centre, which directly handles road andstormwater complaints, will be featured next week.

However, this week I put the various means of logging acomplaint with the call centre, to the test.

We reported a few pothole complaints from readers usingvarious means of communication.

First I contacted the call centre to report a complaint aboutpotholes in Pinetown. My call was answered after four minutes.

The consultant took down facts about the potholes. She alsotook down my contact details. She said the issue should be dealtwith in 10 working days, but acknowledged it might take longer.

In addition, I SMSed a complaint about a pothole in HansDettman Highway in Pinetown. I received an automatic responseat 8.30pm confirming my complaint had been logged.

I also e-mailed the call centre about potholes in Sydenham andstalled construction to repair potholes in Chatsworth.

At 8.20pm I was told my e-mail had been received.A shortresponse was given regarding the delayed roadworks. I was askedto be patient, but was assured my complaint would be dealt with.

READERS identified some potholes.We have reported them tothe relevant municipal unit for action to be taken, and will reportback on progress made in repairing them in the final week of theseries.

●A reader complained about potholes in Stapleton Road,Pinetown, after the intersection with Old Main Road and justbefore the on-ramp to the M13.The closer one got to the bridgeat the M13 on-ramp, the worse it got.The situation was dangerousbecause people swerved to avoid the potholes at the last minute.

● Jey Vasdev complained of potholes in Hans DettmanHighway between Electron and Wiltshire roads, Pinetown. He saidthe area needed urgent attention.

●Another reader complained about potholes in Road 726,Unit 7, Chatsworth. Rehabilitation of the road had begun threemonths ago, but then came to a halt without any explanation forwhy this had occurred.Work had recommenced, but no deadlinehad been given for when the work would be completed.

● Potholes in Sparks Road, just before Spearman Road, werealso highlighted.There were no signs to alert drivers, resulting inthem swerving to avoid the potholes at the last moment.

THERE is a 24-hour engineering call centre that receivescomplaints about road and water issues. Repairing potholes fallsunder this unit.

You can call the toll-free number to report a pothole at080 1313 013, SMS them at 43554, send them an e-mail ateservices@durban.gov.za, or fax them at 031 311 8220.

The Roads and Stormwater Maintenance Department isresponsible for the repairs of potholes and related work on aroad network that spans approximately 7 600km.

In terms of the unit’s service-level agreement, action to repairpotholes must be undertaken within 48 hours of a complaintbeing received at the engineering call centre.

However, bad weather and other unforeseen circumstancescan affect this time period in some instances.

Potholes of a minor nature should be repaired in no morethan 10 working days.

The Roads and Stormwater Maintenance Department has 25operational depots spread throughout the eThekwini area.

Each depot has a dedicated team and a vehicle to repairpotholes.The unit is responsible only for the maintenance of themunicipal road network within the eThekwini region.

WHO LOOKS AFTER WHAT