The Urban Street Design Manual says signals should be spaced and synchronised to desired speeds - which, under its plan, would be 60kph for most urban streets.
Urban superblocks to be broken up
ABU DHABI // On Khaleej al Arabi Road, the well-informed motorist cruises along at a gentle 60kph to catch a series of green signals on the way off the island. Sticking to that speed certainly beats racing from signal to signal, then sitting in frustration at a red light, said Alan Perkins, senior planning manager at the Urban Planning Council (UPC).
The Urban Street Design Manual says signals should be spaced and synchronised to desired speeds - which, under its plan, would be 60kph for most urban streets. Working with other agencies, that could mean vehicles will travel slower on every street in the emirate, Mr Perkins said. But drivers will also enjoy a smoother journey with fewer stops and have more streets to choose from when making a trip.
Having a network of usefully interconnected streets is among the key design principles listed in the manual. The belief is that a connected street network reduces the number of kilometres travelled by providing direct links. When put into place with a public-transport system, "it can decrease congestion and idling rates at junctions and improve overall capacity", according to the manual. The plans to put more access roads through existing "superblocks" will provide shorter driving distances.
Building new streets to improve the "permeability" of the blocks, rather than expanding the number of lanes of existing roads, will help to disperse traffic. The mid-block crossings would also help to eliminate 50 per cent of U-turns, Mr Perkins said. "That takes out the congestion at bigger intersections," he added. U-turns will be restricted on larger streets. Lane transitions, where the number of lanes on a continuous road decreases or increases, will also be limited.
"Blocks in Abu Dhabi are enormous," said Mr Perkins. "Within the block, it is all a massive car park, so there is no actual secondary street system." A public transport system, including trams and a high-speed metro, planned to be in operation by 2016, will help to relieve congestion in the emirate, which is expected to see its population treble by 2030. Tram lanes will, in some cases, run along the middle of the road. The council suggests that streets with public transport can benefit from wider pavements to accommodate stops, shelters and increased pedestrian activity.
Recent changes made by the Department of Transport to Khaleej al Arabi's signalling in the central business district had improved traffic flow, Mr Perkins said. It showed that a change to traffic-signal sequencing could lead to an overall improvement. Traffic lights on Khaleej al Arabi turn green first for vehicles driving straight ahead, then for vehicles turning left. "If we change the traffic signal sequencing more widely across the city, it should reduce congestion at intersections generally," Mr Perkins said.
"It has made a big difference on Khaleej al Arabi." New urban streets will be designed to handle speeds of 15kph to 60kph, though changes to traffic management would need to be supported by enforcement and education campaigns, planners said. Bill Lashbrook, a transport planning manager with the UPC, is confident that "people will learn to stick to the new speeds". @Email:email@example.com