very high design speeds gr revised

Very High Design Speeds Case: GR

Basil Psarianos Nat’l Techn. Univ. Athens, Greece

[email protected]

Transportation Research Board 2006 Annual Meeting

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IN THEORY (GR Design Guidelines 2001)

• Highest Design Speed can be: – 120 km/h (75 mph) in general for

Freeways, but • Can reach the value of

– 130 km/h (~80 mph) in flat topography


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IN THEORY HERE…

The Design Speed is 120 km/h and

The Speed Limit is 120 km/h (75 mph)

but


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WE MADE OUR ALCULATIONS

IN PRACTICE


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IN PRACTICE AND THE RESULT WAS


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IN PRACTICE, for Example Design Speed = Operating Speed = 85% Speed (as of December 2005)

On the TANGENT:

• Passenger Cars: 144 km/h (90 mph) in the driving middle lane (3.50m)

• SU Trucks: 89 km/h (55.63 mph) in the driving middle lane

• Truck-Trailers: 87 km/h (54.38 mph) in the driving middle lane

• Buses: 98 km/h (61.25 mph)

Corinth-Athens Freeway, St.:57+550

Speed Limits (km/h):

120 for PCs, 80 for SU Trucks, 70 for Truck-Trailers, 90 for Buses


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IN PRACTICE, for Example Design Speed = Operating Speed = 85% Speed (as of December 2005) On this SHARP HORIZONTAL CURVE with R=400 m (1311 ft): Passenger Cars: 128 km/h (80 mph) in the driving right lane (3.50m)

Athens - Salonika Freeway, St. 98+000

Posted Speed : 90 km/h (56 mph)


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Fast & General Conclusions 1. Inconsistencies between Theory

and Practice in various Design Aspects

2. High Design Speed Highways are OUT THERE; we in GR & EU do not want to admit it and perhaps face it!