Saturday, 5 September 2009

Twenty's Plenty for Bristol

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.


Docsavage said...

when they make old market street 20MPH then I'll celebrate!

in terms of changing the signs, surely a decent sticker rather than a replacement would suffice - it'd save money.

sadly this initiative could end up like the various 'no drink zone' areas - I love cycling past the signs showing 'no street drinking' (st judes and Turbo island spring to mind) and seeing the crowds of drinkers gathered at the base of the signpost!! unless it's enforced, whats the point.

Chris Hutt said...

Hi Doc,

I see this as one step along a long journey. In itself it doesn't change a lot but it all helps to edge things slowly towards lower speeds. Of course the slow speed of change can be frustrating but real change takes time.

If speeds were reduced by just 1 mph per year you probably wouldn't notice much from one year to the next, but after ten years things would be very different. That's how things are changing and this is part of that process.

Docsavage said...

yup,I guess it's like the attitude to smoking. In a relatively short period smoking has(thankfully)been made to be percieved as an anti social activity, and that should encourage its decline. I'd hope the efforts to curb speeding are similarly sustained in the long term to effect real results.
(but as a cyclist I'd still like a bit more enforcement!)

Forest Pines said...

I'm puzzled by Dean Lane being marked as a busy-enough-for-30mph route all the way along. I frequently use Dean Lane on foot: most of the traffic on Dean Lane also uses Catherine Mead St and St John's Road, with relatively little traffic along Dean Lane between the end of Catherine Mead St and Coronation Road.

Really this looks like one of those on-the-cheap programmes - they may need a lot of signs, but signs are a lot cheaper than building work. To my mind, it would be more effective to have more "no through traffic, access only" areas like Windmill Hill. It would also be useful, if we're talking about reducing speed on the busier roads, to have differential speed limits so that buses could get a speed advantage over other traffic. Not much help except when roads are quiet, of course, but still a little help.

Incidentally, I recall that in Hull, part of the city ring road has a 20mph speed limit with speed humps! I can't imagine that happening here, somehow.

Anonymous said...

No enforcement, no point.

Nearly hit by a motorist doing 50 mph in the Church Road 20 mph Zone today.

I wish these academics a bicycle lift loonies would get real.

David Hembrow said...

We've got over 30000 km of 30 km/h roads in the Netherlands. While initially the danger to cyclists was quite markedly reduced on these roads, injury rates on these roads have increased over time as drivers became more used to the lower speed limit, so drove faster again.