20 MPH Area

headpin

There are now many 20mph zones springing up all over the place. Most that I have seen only have a pair of 20 mph signs as you enter the zone and then 30 mph signs (or higher where applicable) when you leave the zone. Within the zone (and they can cover very large areas) there are no repeater signs to indicate that you are in such a 20 mph zone.

The general rule is (or was?) in England and Wales (possibly all the UK?) that if there are street lamps and no other speed limit is posted, including the necessary repeater signs, the default limit is always assumed to be 30 mph. This rule appears to have gone by the wayside in 20 mph zones. So, my question is, does anyone know which piece of legislation gave local authorities the ability to introduce 20 mph zones and more importantly where does it advise on the rules on posting the 20 mph limits? This is potentially very importnat as if you park in a 20 mph zone, in an unfamiliar area, you may natural assume that when re-commencing your journey that you are in a normal 30 mpp zone if there are no rerpeater signs advising you of the lower limit that applies.

Potentially this is a real problem area. Surely the law does not leave both a 20 mph and a 30 mph as a default situation? Chaos surely. And, how enforceable would it be if you were prosecuted or issued a Fixed Penalty Notice by your friendly local enforcement officer??

Advise and discuss please.

anewman

As my driving instructor always said, you've got to be looking for the speed limit signs - if you don't look you won't know the limit.

movilogo

Urban area with street lights = 30 mph unless repeater sign tells you to go faster or slower (20 mph areas are almost always with speed humps)

Rural area = National Speed Limit unless repeater signs tell you to go slower

nealallen

Here's a link to the Depatment of Transport http://www.dft.gov.uk/pgr/roads/tpm/tal/trafficmanagement/20mphspeedlimitzones

Now I've read it but it does explain the 20mph laws.

anewman

I know some 30mph zones with speed bumps.

headpin

nealallen wrote: »

Here's a link to the Depatment of Transport http://www.dft.gov.uk/pgr/roads/tpm/tal/trafficmanagement/20mphspeedlimitzones

Now I've read it but it does explain the 20mph laws.

But it doesn't explian the anomoly of there now appearing to be two default speed limits. So how do you decide which applies? 20 mph or 30 mph? And, as said above, in my locality there are many places in 30 mph areas that have traffic calming measures, so that cannot be assumed to be a guide or otherwise.

I would not rely on DfT guidance as it is not legislation and the person that compiled it is probably not aware of the overall law relating to speeds generally and the default provisions. Othewise they would surely have addressed this particular and important issue? You cannot be silent on it. I would suggest that this is yet another example of a Civil Servant !!!! up! Sad but true.

Inactive

Many 20 mph zones are not legally binding, they are purely advisory, usually near schools.

greenman7

AA Fuel for Thought research results:

1 30mph/20mph/speed humps petrol car consumption figures

Steady 30mph (4th gear):
60.7 mpg (small petrol car), 55.6 mpg (medium petrol car)
= 58.15 mpg (average)

Steady 20mph (3rd gear):
55.5 mpg (small petrol car), 49.1 mpg (medium petrol car)
= 52.3 mpg (average)

Speed humps (6 over 1/2 mile at 20-30 mph):
33.8 mpg (small petrol car), 27.9 mpg (medium petrol car)
= 30.85 mpg (average)

30mph/20mph/speed humps petrol car consumption differences

Change 30 mph zone to 20 mph:
increases fuel consumption by 5.85 miles per gallon, or 10.1 per cent.

Add speed humps to a 30 mph zone:
increases fuel consumption by 27.3 miles per gallon, or 46.9 per cent.

20 mph zones are not that good for the environment with about a 10% increase in fuel consumption.

Wig

I have sought to put the legislation (below) into my own words for easier reading & understanding.

The legislation under which speed limits -other than restricted roads- become law is the Road Traffic Regulation Act 1984 - Part IV - sect 84(1) & 82(2)
http://www.statutelaw.gov.uk/legResults.aspx?LegType=All+Legislation&title=Road+Traffic+Regulation+Act+1984&searchEnacted=0&extentMatchOnly=0&confersPower=0&blanketAmendment=0&TYPE=QS&NavFrom=0&activeTextDocId=2223862&PageNumber=1&SortAlpha=0

The legislation under which they are signed is the TSRGD 2002
http://www.statutelaw.gov.uk/legResults.aspx?LegType=All+Legislation&title=Traffic+Signs+Regulations+and+General+Directions&searchEnacted=0&extentMatchOnly=0&confersPower=0&blanketAmendment=0&TYPE=QS&NavFrom=0&activeTextDocId=2917794&PageNumber=1&SortAlpha=0

First we need to recognise there are 2 different areas they are "20 limit" and "20 zone".

Repeater requirements are in Schedule 19 Directon 11(2) Repeaters must be placed except as to (3) & (4)
11(3) 20mph repeaters need not be shown where a "20 ZONE" sign has been placed on all road entry points.
11(4) The repeater signs shall not be placed
(a) On roads with close lamp posts which are also 30mph. Thus speed limits of 20mph need repeaters.

Direction 16 (1) (Schedule 19)
A "20 ZONE" sign can only be placed if within the zone there are "traffic calming features" at least every 100m, except cul-de-sacs not more than 80m long.
"tcf"s as defined in 16 (2)
*road hump
*a refuge for pedestrians
*a variation of the relative widths of the carriageway or of any footway which reduces the width of the carriageway
*a bend in the carriageway > 70°
*build-outs
*chicanes
*gateways (England and Wales only)
*islands
*overrun areas
*pinch-points
*rumble devices

The signs themselves are in Schedule 2-TSRGD

Sect 81of the 1984 Act says you can't drive faster than 30mph on restricted road.

Definition of restriced road
S82 of the 1984 Act
82 subject to 84(3)
(1)Restricted road is one with close lamposts
(2) There may be an order made to withdraw or apply restricted road status from/to any road.

Section 84(3) If an order is so made by 84(1)(a), that road shall cease to be a restricted road.

Section 84(1)(a)An order can be made to apply any speed restriction to any road.
Thus from 82(2) & 84(1)(a) an order for less than 30mph may be made, and if so, the road would no longer be "restricted" i.e. 30mph.

Section 85(5) In an offence under S 81, evidence of the absence of repeater signs, shall indicate that the road is a restriced road (not exceeding 30mph).

Conclusion
Nothing that I have read, indicates that correctly signed 20 limits or 20 zones are unenforceable.

There is a slight inconsistency in 85(5) because the same can be said of a "20 zone". However 85(5) is only referring to a sect 81 offence of exceeding 30mph, and if you were in a 20 zone you would see TCFs every 100m
And if you had TCFs every 100m you might find it difficult to exceed 20mph. Assuming you did exceed 20 and got caught and prosecuted, you could defend yourself on the grounds that it is established in legislation that "evidence of the absence of repeater signs is evidence that the road is 30mph". How far you get is for the courts to decide.

tomstickland

There's a bit of a feeding frenzy for 20 limits near me. Because some of the pilot studies were done on roads that needed improvement and a 20 limit was possibly sensible, the stats morons now think that they can extrapolate this to every urban road regardless of the specifics.

I'll find the link later. Cirencester want to make the entire town (within the ring road) a blanket 20 limit so that they can do it with a handful of signs rather than 100s of them.

A friend of mine has had his area "improved". That means bolting very steep bumps to the road every 40m, islands and a sea of 20 signs. It's appalling for economy. I used to cruise through carefully at 25mph. Now I brake, crawl over bump at 4mph, then accelerate up to speed. Repeat about 8 times. Improvement in road safety about zero. I spend about 30% of the time staring at the bumps, 30% of the time ranting about how crap it is and abotu 42% of the time wishing I was better at maths. I think that the locals are going to quietly remove some of them.

Wig

Tom,

If they had more sense and they wanted the whole area to be 20, they could acheive that by using rumble strips every 100yds, these would be a lot less intrusive on the drivers.

Restriction on the construction of rumble devices
6. Where a rumble device is constructed or maintained in a highway–
(a)
no vertical face of any material forming that device shall exceed 6 millimetres measured vertically from top to bottom of that face; and,

(b)
no part of the device shall be more than 15 millimetres above the surface of the carriageway.