TRAFFIC experts have unveiled a series of radical measures which will be used to combat rat-runners if the city’s road tolls scheme gets the green light.
It comes after it was revealed that vehicle numbers on some streets will soar as drivers seek to dodge the planned toll-cordon cameras.
The public inquiry into the congestion charging scheme heard claims that steps such as speed bumps, traffic light "rephasing" and 20mph zones could be used to tackle rat-run hotspots.
Neil Johnstone, director of the Edinburgh-based Halcrow Group, told the inquiry that specific solutions had been developed for different parts of the city.
The traffic engineering firm had been hired by Transport Initiatives Edinburgh (TIE) to prepare a study on the problem.
Leith Walk, Canonmills, Inverleith and the Botanic Gardens, Dalry-Blackhall, Corstorphine, Marchmont, Morningside, Queen’s Drive, Duddingston and the B701 were all identified as potential targets for rat-runners.
Mr Johnstone said the aim was to reduce the "attractiveness" of these areas among motorists and discourage their use. Among the list of measures designed to cope with toll evaders is traffic light rephasing where signal changes will be slower. Lights will take longer to shift from red to green, lengthening journey times.
Speed bumps will also be used, while 20mph zones will be introduced in residential areas and close to schools.
Restricted turns and one-way systems will also be used in some areas, while new pelican crossings and central refuge islands will be built.
Douglas Armstrong, the advocate for Fife Council, asked Mr Johnstone how a predicted 13 per cent surge in traffic on Queensferry Road during morning peak times could be justified. Mr Armstrong put it to Mr Johnstone that "far from any reductions due to road tolls, there will be a massive increase".
Mr Johnstone claimed that such a rise in vehicle numbers "does not necessarily result in congestion".
He added that traffic growth forecasted for other streets would not always be apparent in reality.
He said: "If you have a street where 100 cars pass in one hour, then a 20 per cent increase would not be noticeable."
Last month, road toll critics hit out at city transport chiefs after it was revealed that the Halcrow Group had predicted traffic growth of 550 per cent on Annandale Street in Broughton if the scheme went ahead.
Among other badly affected areas will be Bellevue Place and Green Street, also in Broughton, which will suffer increases of almost 300 per cent, while Inverleith Terrace, near the Royal Botanic Garden, will see a rise of nearly 200 per cent.
The use of traffic-calming measures have already come under attack for worsening the problem on certain roads in order to improve the situation on others.
Mr Johnstone said that some streets may see "significant" changes in traffic rates but this would be outweighed by the "overall impact" of road tolls.
He explained that direct routes into the city centre would witness a reduction in traffic levels due to the charge.
But roads around the edges of the cordon would experience increases as drivers sought to avoid the toll.
Mr Johnstone said: "This was not about radial versus orbital routes. We have tried to formulate a mitigation strategy as part of a balanced process.
"The prime objective was to mitigate traffic flow increases in sensitive areas and make sure it would be balanced in the treatment of suburban areas.
"We sought to encourage the spread of traffic across the network."
The crackdown measures
Traffic-light rephasing and the prioritisation of particular movements will be used between Easter Road and Broughton Road in Canonmills, as well as Annandale Street and Brunswick Road. The aim is to discourage drivers trying to avoid the cordon charge at the top of Leith Walk.
Inverleith-Royal Botanic Garden
Traffic-calming measures and the creation of safer crossing environments will be used to put off motorists attempting to avoid the inner cordon. These steps will seek to reduce traffic flow on Inverleith Row, Inverleith Place and East Fettes Avenue.
The mitigation strategy will be to encourage more appropriate routes and discourage rat-running through streets in the Murrayfield area. A significant traffic increase is predicted between Slateford Road and Gorgie Road in the Murieston/Dalry area and Hillhouse Road/Queensferry Road. Ardmillan Terrace, Russell Road and Murrayfield Road would be among the streets affected.
Traffic-light rephasing and prioritisation measures will be used to channel traffic onto the higher standard roads in the area. It is anticipated that drivers will use the Corstorphine area between Hillhouse Road/Queensferry Road and Calder Road/Gorgie Road to try and avoid the outer cordon. Saughton Road and Corstorphine High Street were seen as potential rat-run hotspots.
Traffic-calming measures restricting certain movements will be implemented. Traffic flow from Comiston Road, Morningside Road and Bruntsfield Place to Dalkeith Road and Old Dalkeith Road is anticipated to rise, while left-turning vehicles from Melville Drive into Marchmont Road were identified as part of a wider inner cordon avoidance manoeuvre.
Traffic-mitigation measures will be used in combination with area-wide traffic calming. Increased traffic movement is predicted between the inner and outer cordons through the Morningside area between Dalkeith Road/Old Dalkeith Road/Minto Street/South Clerk Street, and Lanark Road and Slateford Road.
Queen’s Drive has been highlighted as an attractive route to potential rat-runners. Any proposed mitigation strategy on this route will have to be agreed with Historic Scotland.
Traffic-light rephasing will be used to cope with the expected traffic growth in Duddingston, as this is a through route for traffic from the north and east, to the south and west areas of the city.
The B701 presents a route around the city without crossing the outer cordon, running from Drumbrae in the west to Gilmerton in the east, via Corstorpine, Sighthill, Wester Hailes, Colinton and Gracemount. It may be difficult to discourage traffic away.