Although the average speed in towns is 30, Brake, the road safety charity is calling on drivers across the capital to take their foot off the accelerator and drop down to 20 mph.
The company is running a campaign entitled GO 20, which it hopes will save lives by reminding
motorists that they should exercise caution when driving near schools, shops and people's homes.
Brake believes that an advertising campaign will highlight the issue and may encourage the government to change the law so that 20 mph becomes the average speed of drivers in built-up areas of the country.
Deputy chief executive of Brake Julie Townsend said that the campaign is about making sure that "everyone should be able to walk and cycle without fear or threat".
She said that the adverts aim to be "engaging and empowering rather than finger-wagging", which will no doubt please many motorists, as it is never nice to feel you are being pressured into driving a certain way.
Ms Townsend hopes the "vital message" that reducing speed is "a really positive thing drivers can do to make [the] streets people-friendly" will be welcomed by the nation's motorists.
It's not only speed that can affect how safe a moving car is in a built-up environment, ensuring your vehicle and its wheels are regularly checked and serviced is vital to securing you and your passengers' safety.
The Royal Society for the Prevention of Accidents (RoSPA) explains on its website the important role that tyres have to play in keeping drivers, their passengers, and others on the road safe.
It highlights the critical relationship between a tyre's tread depth and its efficacy.
Driving a car which has inadequate tread depths can be dangerous as it reduces the traction of the car on the road and that affects its ability to brake effectively. This is a particular problem when cornering or driving in wet conditions.
"A tyre is unable to deal with the same volume of water on the road at lower tread depths, which means that the tyre is unable to transmit traction and braking forces to the road as effectively," RoSPA explains.
The organisation points to a test carried out by the British Rubber Manufacturers Association, which revealed that stopping distances increased significantly on wet roads when a tyre's tread depth was below three mm.
The current legal limit for a tyre's tread depth is 1.6mm but the test showed that at this level stopping distance increased by 36.8 per cent when a car was driven on hot rolled asphalt.
RoSPA therefore recommends that drivers change their tyres once the tread depth reaches three mm in depth.
Not only do tyres with the wrong tread depth have problems stopping quickly enough, incorrect tyre pressure can significantly affect a vehicle's safety.
Tyres which are either over or under inflated will not make contact with the road properly and this will in turn increase the tread wear, and possibly the stopping distance.
Drivers are urged to check their tyre pressure on a regular basis, particularly during the winter months when driving conditions can be more treacherous.
Visit ATS Euromaster to get your car regularly serviced.
Posted by Brake, a road safety charity, announces the launch of its GO 20 campaign.