Why speed signs should be removed

Speed signs should be removed from most urban roads.  They are not necessary in most places, hazardous on the roadside, waste tonnes of steel and distract drivers from their main task.

The design of speed signage is arranged to prove you wrong not help you get it right.  There is a better, safer and more environmentally-friendly way.  The explanation is about the difference between discrete information and continuous information.

Signs are discrete; meaning you see them every now and then along the roadway.  There will be one at the change of limit zone and then every so often within the zone.  wherever you are there is a limit.  You might not be able to see the sign but it can be proved what limit applies by reference to a sign further back on the road.  Thus the signs can prove why you have done something wrong but they are not well designed in terms of helping people to get it right.   The problem is that at any given moment you can not necessarily see what speed limit applies.  So you either:

(a) drive at the default (50km/hr in urban areas in Victoria, Australia); or

(b) guess; or

(c) go with the traffic; and

(d) all the time be distracted from the main task by looking for signs.

If you do (a) you risk going far too slow compared to other people thus increasing overtaking movements and be subjected to tailgating, road rage, etc.  If you do (b) or (c) you will get fined if you are ultimately wrong.  All of these involve looking around for signs and thus less concentration on the road ahead, checking mirrors, etc.  That is why the system of signage – when coupled with strict enforcement – has an element of danger in its design.

A better way is easy, free and provides continues information – next post.

About John Culvenor

Hi, Thank you for taking a look at this blog. I work in engineering, ergonomics, creativity, design, training, etc. Often this is about helping solve legal puzzles through accident analysis. Sometimes it is about thinking up better designs for equipment, workplaces, and systems. This blog is about good design and bad design, accident analysis and how it can be done better, and how we can make a better, safer world by design!
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7 Responses to Why speed signs should be removed

  1. Kevin Jones says:

    John, the CEO of VicRoads discussed the issue of redundant road signage at a lunchtime interview only yesterday. He said that one audit of a particular site removed dozens of unnecessary signs and that too often we impose additional controls instead of simplifying what is already there.

    • Hi Kevin, Thank you. Well that’s a move in the right direction! I am talking about going a long way further as in getting rid of all of them as a default with a new and better concept using existing design features of the roads to indicate the limit (some signs would be needed where the default is not appropriate).

      John Lambert’s concept is another interesting idea which has great potential and I want to explore that as well.

  2. johnlambert235 says:

    And I thought I pushed the boundaries! Agree with the approach. I have been promoting since 2004 that speed enforcement using speed camera technology should monitor average speeds and then infringe those travelling more than 9 km/h faster than the average or more than 19 km/h slower than the average (with exceptions for emergency and slow moving vehicles)

    • Thanks John. Your idea is interesting. If I am catching on, you say that the speed limit could be dynamically set by the users of the road. That is a pretty useful idea. It could be enforced like this, set up a speed camera, it monitors speed for say 15 minutes and computes the mean and standard deviation, and then books those that are too fast as statistical outliers.

      Actually I was going to move on to the replacement for signs with a different idea – but I like yours as well!

  3. Jahan says:

    I have a relative that works with the military in avionics who totally agrees (and quoted some research to back it up) that the current system on speed limit signage is a distraction and causes more accidents than speeding itself.
    Personally, I don’t like the idea above of fixed points cameras if it means employing them in remote parts of the country as I believe that it is a case of driving to the conditions on open roads and a performance based speed limit should apply.
    I travel regularly in parts of the country where the worst thing that you can hit is a fence post, and as someone who is very time poor, I travel well above the allowed speed limit, but will argue that due to the vehicle that I drive and that being an alert and healthy person with very good reaction reflexes that I do not drive dangerously in doing so.

    • Thanks Jahan, You raise some interesting points such as (a) Distraction. There are usually downsides to any intervention and this is one of them in relation to speed limits – especially when coupled with strict enforcement. (b) The same limit for vastly different circumstances. (c) Whether something is dangerous versus simply over the limit. Thank you for your contribution.

  4. Pingback: Speed limit design the easy way – the proposal Vicroads rejected | safedesign

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