Bristol City Council have announced plans to trial a widespread 20 mph speed limit in two areas of the inner city, centred on Easton and Southville as shown in the map below bounded by the blue lines. Consultation on the general arrangements takes place this month but there will be an opportunity to object to specific Traffic Regulation Orders (TROs) when these are subsequently put forward. Implementation is planned for next spring. The plans were actually leaked back in January and the current proposals are much the same as those shown on the leaked maps.
View 20 mph in Bristol in a larger map
The idea is that 20 mph should replace 30 mph as the normal, default speed limit in residential areas of the city although without the introduction of physical traffic calming measures or police enforcement. Some people have expressed scepticism about the effectiveness in the absence of such enforcing measures but experience elsewhere suggests that average speeds will be slightly reduced as a consequence of changing the notional limit. Nevertheless the idea seems surprisingly popular with the general population so very much an idea whose time has come.
But there is, predictably, a major problem with the current proposals, leaving aside the enforcement issue. The plans exclude most main roads in the areas concerned (red lines in the map above), even when those main roads are also shopping streets, designated cycle routes and serve schools and parks. Precisely the sorts of roads that most need to have lower speed limits. The two most glaring examples are perhaps Mina Road in St Werburgh's and Dean Lane in Southville, but there are many others like North Street (Southville) and Stapleton Road (Easton), both important shopping streets that serve as focuses (or foci if you like) for their respective communities.
So what is the big problem about applying 20 mph limits to main roads? It's actually been tried and tested here in Bristol with a short stretch of the A420 Church Road in Redfield (pictured above and shown as a green line on the map). Admittedly it's not very obvious that it makes much difference, but then it is still the exception to the general 30 mph rule and unlikely to be taken much notice of. But at least it establishes that 20 mph on main roads in residential and shopping areas does not bring the world grinding to a halt. Everything carries on much the same but with speeds gradually edging downwards.
Another big problem with having so many streets excluded is the need to sign all the transitions from 30 to 20 and back, as pictured above with the existing 20 mph zone just south of Church Road. Not only do all the signs cost us money but they add to the general clutter on our streets and result in road users losing track of whether they are in a 20 mph or 30 mph street.
What we need is for 20 mph to replace 30 mph as the general speed limit on all urban streets except those roads that are clearly not residential like Easton Way, the Portway and of course the M32. The 20 mph default needs to be consistent and ubiquitous and not something confined to backwaters where speeds rarely exceed 20 mph by much anyway. The current propsals, even though claimed to benefit cyclists and pedestrians and to be funded by Cycling City money, will do little for cyclists or pedestrians where they experience the most intimidation and danger, on the main roads which are set to be excluded.