Is our new 20mph zone working?

Haringey Council have just spent £100,000 on the new traffic calming scheme for the Harringay Ladder. I'm keen both as a resident and as a ratepayer to be satisfied that the new scheme is working as well as possible.

Ideally this could be judged by measuring levels of reduction in traffic and in traffic speed. Sadly, however, Haringey Council set no targets for the scheme, so we'll have to develop our own criteria.

Perhaps for speed we could simply say the success criterion would be that traffic is adhering to the 20mph limit. As for levels of traffic, I can only think of, does it feel like there's less traffic. Unsatisfactory, I know, but in the absence of proper data collected by the Council, it's about all we got.

I came to thinking about this a couple of weeks ago when I was being beeped by cars behind me on Wightman Road because I was driving at 20mph.

"It is 20 now..........isn't it?", I wondered. But I wasn't sure. And I'm not surprised I wasn't sure. There's not a lot of signposting. There's one roundel sign on Wightman just before Sydney Road together with the limit painted on the road at the same point. Then nothing till just before Hewitt when once again the 20 mph limit is painted on the road.

The red faced fuming motorist behind me could be forgiven for not being aware that he was in a 20mph zone.

Something similar happened today on my way home. So I found myself wondering what's best practice signposting in 20mph zones.

Here's what I found. Apparently there are two legally defined ways to introduce a 20mph limit. One is through the creation of a 20mph zone; the other is by introducing a simple 20 mph limit.

20 mph zones

The purpose of 20 mph zones is to "create conditions where drivers naturally drive at 20 mph because of the general nature of the location, or as a result of traffic calming measures".

Department for Transport Guidance says:

20mph zones are most appropriate in areas where an urban safety strategy has been developed, involving measures to discourage through traffic from using the proposed zone. the zone itself will normally be residential in character, although other areas such as shopping streets may also be appropriate. The road network within the zone should generally consist of access roads, but the inclusion of some local distributor roads may be acceptable. In order that zones do not become too large, no road within the zone may be more than 1km from the boundary of the zone.

According to the Traffic Signs regulations and General Directions 2002 (TSRGD) an area is legally a 20mph zone when 20mph zone signs are used. This comes with certain legal obligations. In particular Direction 16 of the TSRGD stipulates that no point within the zone must be further than 50 metres from a traffic calming feature (unless in a cul-de-sac less than 80 meters long). Direction 16 also gives full details of what is a traffic calming feature.

The zone sign at the zone entrances is only required to be erected on one side of the entry road where the road is less than 5 metres wide. However, it is recommended that even in these situations signs should be placed on both sides of the road. This helps to accentuate the gateway effect and the feeling for the driver of entering an area which is "different".

Apparently in 20mph zones no other indication of the speed limit is required other than at EVERY exit and entry point. I presume this is because the traffic calming measures should mean there is no need.

20mph limits

A 20mph speed limit can be introduced using standard speed limit signs without the word Zone. Direction 16 of the TSRGD does not apply and traffic calming features are not necessary. However, 20mph limits are really intended to be used only on roads where the traffic speed is already below 24 mph and where physical enforcing measures are not therefore required. However, if a 20 limit is ordered the Road Traffic Act requires 20 mph repeater signs to enable the speed limit to be enforced.

So a few questions for me:

1. Does our area have "an urban safety strategy... involving measures to discourage through traffic from using the proposed zone"?
2.Does our 20 mph zone "create conditions where drivers naturally drive at 20 mph because of the general nature of the location, or as a result of traffic calming measures."
3. Is it legally set up, that is a) entry & exit signs b) traffic calming every 50 metres.
4. Following DfT best practice recommendations, are our zone signs placed on both sides of the road to create a gateway effect?
4. Is it being effective at keeping speeds to 20 mph.

My view is that there's something amiss with the signposting. I'm not sure if we have them at every entrance and exit, but even if we do, I think we need repeater signs to drive home the point. In Camden they've experimented successfully with speed activated flashing signs. OK, expensive, so perhaps just some more repeater roundels.

I'd also like to see some enforcement which I think is, or is about to become a Harringay Policing priority.

So, I'd welcome views from other people. But ultimately, I'd like to agree what we think is a sensible course of action. It may be that people feel that no action is required.