From Chris Hamshar at Kingston

I wonder if you can help me with a question raised by our Chair of  the Transport and Infrastructure Overview Panel.

He is asking whether or not it is actually illegal to promote a 20mph zone without self enforcing traffic calming features. The emphasis here being on illegal as he is already aware of the stated views of the police who require such features and who would presumably formally object to a traffic order promoting  a proposal without such features.

Have you any knowledge/experience  which can help me on this or direct me to anyone who might help. I have obviously asked our Solicitor but it may be that one or other of you has already investigated this matter.

I need to get back to the Councilor before Committee next Wednesday and would appreciate any help you can give.

Many thanks

Chris Hamshar
Head of Highways and Transportation
Royal Borough of Kingston

Response 1)

It is not illegal. Refer you to Traffic Advisory Leaflet 9/99 on 20 mph. Note the section on existing 85%ile speed

A number of authorities have schemes with no physical measures. Bromley has a scheme, Maple Road, with only few speed reduction features.

You are required to consult with the Police and to take account of the Police's views but you do not have to accept their objection and can override them.

The Institution of Highways & Transportation are publishing new guidelines on traffic calming. I suggest that you contact Tersa Coyle at the IHT details below to get a name of one the authors and speak to them for the up to date advice and case studies
Gareth Davies
Assistant Director (Transportation Planning)

LB Bromley

Response 2)

Response 3)

Gordon Bell
London Borough of Richmond upon Thames

Response 5)
It depends on what signs you use to indicate the speed limit.  If you want to use the sign to diagram 674 which specifically includes the word "zone" then Direction 16 of the Traffic Signs Regulations and General Directions (TSRGD) applies and requires that "no point on any road (not being a cul-de-sac less than 80 metres long), to which the speed limit indicated by the sign applies, is situated more than 50 metres from  a
traffic calming feature".  It then goes on to list what constitutes a traffic calming feature, essentially those things identified as such in the Traffic Calming Regulations and road humps but there are some other things mentioned (refuge islands, carriageway narrowing and sharp bends).  If 20mph Zone signs are used it is therefore a legal requirement that traffic calming features are also installed.  Such
zones are usually introduced over an area covering several roads, say around a school.
If you just want to introduce a 20mph speed limit using standard speed limit signs to diagram 670  (ie 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.  To erect them in other places where this is not the case would have no real effect and any proposal to do so would probably be resisted by the police.  Traffic Advisory Leaflet 09/99 and DETR Circular 05/99 provides the detailed guidance on all of this.
Regards
Bill Heale
Principal Engineer, Traffic Management
(Central Area)
London Borough of Harrow

Response 6)