Drivers living and working in the country’s main towns and cities are on average travelling more slowly than they were in the same areas five years ago.

The latest statistics from the Department for Transport (DfT) show that in 2004 during peak times 30% of travelling time was spent at speeds under 5mph, while 50% of time was spent at speeds under 20mph. This represents an increase of 2% and 0.6% respectively in the amount of time spent travelling at low speeds on five years ago.

The figures will confirm what many motorists have long suspected, that increased congestion, road works and bad road planning are making journeys longer and more stressful. It may also provide ammunition for those who support congestion charging schemes to ease traffic flow. In 2003, the first year of the congestion charge in London (which is excluded from the survey) the average speed of traffic increased by 37% to 11mph from 8mph during the previous year.

Of the areas surveyed by the DfT (Britain’s 18 largest towns excluding London) the lowest average traffic speed at peak time was Leicester (15.5mph) followed by Nottingham (16.9mph) and Bristol (17.1mph). Tyneside recorded the highest average speed at 21.9mph.

Across the country the average speed of urban motorists is 21mph during peak time. When motorways are excluded this drops to 18.8mph. Not all areas surveyed recorded a slowing down of traffic.

In Greater Manchester average speed rose 2.9mph.

Black box is the new speed cop

A new anti-speeding device is being installed in cars to report drivers who go over the limit. The device has been developed by IBM, the computer giant, and is being tested in the United Arab Emirates, which has one of the world’s worst traffic accident rates. If a driver speeds, the black box sends a signal to a control room where the vehicle, its speed and location are recorded by a computer.

IBM says the technology can be installed in any vehicle, raising concerns that it could one day take over from speed cameras. “This has the ability to redefine traffic management,” said Lia Papa, an IBM spokeswoman. “It could change the way traffic is managed in cities and countries around the world.”

The system will be used initially in the UAE as part of a four-year $125m (€102m) agreement between IBM and the government to help improve road safety. In the UAE, which has about 2m drivers, one person is injured every two hours and one person dies every 15 hours, according to government research.

The box will be installed in tens of thousands of cars and data will be monitored by the Ministry of Higher Education and Scientific Research, which will use the system initially for research. In future it could be used to allow police to monitor drivers.

The device checks the speed of a vehicle and compares it with the relevant speed limit using the global positioning satellite system. As well as reporting the driver, the box will sound an alarm inside the vehicle.

Cashback plan for clean cars

The Treasury is considering plans for a cashback scheme for environmentally friendly cars. Drivers who buy vehicles such as the Toyota Prius or Lexus RX 400h would get a cheque from the government of up to £150 while owners of less fuel-efficient cars would pay more in road tax.

The proposals have been drawn up by the Energy Saving Trust, which is funded by the Department for Transport (DfT) and is the government’s official adviser. The trust wants a new top level of road tax — band G — for vehicles emitting more than 210g/kg of carbon dioxide (CO2). Band G would cover cars such as Range Rovers and the BMW 7-series and would attract road-tax charges of up to £900. Owners of vehicles in the bottom bands would pay little or no tax and might qualify for cashback.

The trust compared the system — known as fee-bating — to Robin Hood. “It is the CO2-rich giving money back to the CO2-poor,” said a spokesperson. The trust claims that existing tax differentials are too small to encourage people to buy low-emission cars, citing the increasing popularity of 4x4s as evidence.

Existing tax bands, which came into force on April 1, run from A (for vehicles with CO2 emissions of less than 100g/km) to F (above 185g/km), with rates for petrol cars ranging from £65 to £165 per year.

DfT research claims it would take a differential of £150 between bands to persuade the majority of new-car buyers to switch to a lower tax band.