Narrower lanes will cut speeding

In a city with streets that are more like rural highways, roads will be made safer while journey times stay the same.

Photo from the Urban street manual, Plan Abu Dhabi 2030
photo shows a good crosswalk
Courtesy Abu Dhabi Planning Council

ABU DHABI // In a city with streets that are more like rural highways, motorists travel dangerously fast through areas packed with pedestrians. But under the Urban Street Design Manual, roads will apply the brakes to such behaviour. "Usually it is put down as being the behaviour of the driver that is the problem here," said Alan Perkins, a senior planning manager at the Urban Planning Council (UPC).

"In a way, we've got a whole system that is designed to encourage drivers to drive quickly." Planners hope that changing the infrastructure will change the way people drive. Out with the right-turn lanes with long, sweeping curves that allow cars to pass through at speeds greater than 40kph. Goodbye giant roundabouts with no safe pedestrian crossings. Farewell to the wide lanes on urban streets that are more suitable for high-speed motorways.

In their place will be tighter right turns that force cars to slow to at least 15kph. Roundabouts will have two lanes at most or be replaced with more pedestrian-friendly junctions with signals. And, as population density increases, traffic lanes will narrow. "The lanes are too wide at the moment," Mr Perkins said. "Typically, in North America, the lane width you would use for a highway lane is the standard for a city street in Abu Dhabi."

The UPC says the manual's safety goals will be achieved by making the system's most vulnerable users - pedestrians, public transit users and cyclists - a high priority. Mid-block intersections, experts say, could benefit all three groups. Such a design breaks up long city streets, creating an additional pedestrian crossing and relieving traffic congestion by providing another route for cars. U-turns will be restricted on larger streets to protect pedestrians. When they are permitted on boulevards and avenues, they will be placed before crossings, eliminating conflicts that often occur with pedestrians.

Although it is up to municipalities and police to post speed limits, the manual recommends varying speeds depending on street types. For instance, on a city boulevard, defined as a street with three lanes passing through areas with buildings of seven stories or more, a speed of 40kph is recommended. In a commercial zone, that increases to 60kph. Synchronised signals that allow traffic to progress at stable rates will encourage motorists to obey speed limits, the UPC says.

That would curb the habit of racing between signals only to wait at the next red light, said Bill Lashbrook, transportation planning manager at the UPC. "Our goal is to improve the route, not to reduce capacity, but to improve the progression between the signals so your overall journey time will remain the same or possibly slightly improve," he said. "If you break that up by tightening the lanes, adding an additional signal between, then you use smart strategy to co-ordinate the signals. Your overall journey time will remain the same but your speeds will be much slower."

Pedestrians have a 90 per cent chance of survival if struck by a car travelling at 30kph, but that falls to 50 per cent if the speed is 45kph. The plan aims to provide better lighting to aid night driving. Well-designed lights have been shown to reduce pedestrian accidents and promote the use of public streets and spaces at night, experts say. On retrofit designs for existing streets, light fixtures nearer the street could be mounted on existing light poles.

The design manual includes standards that address public transport and cycling, forms of transportation expected to significantly grow in popularity under Plan Abu Dhabi 2030. The plan puts Metro and tram stations within 200 metres of major destinations. Cycling facilities are to be included in every new street plan. Emergency vehicles, meanwhile, will be allowed to use bicycle paths and lanes and to mount pavement kerbs or raised central reservations to bypass traffic.