This last two weeks the question of road signs has come up again... the UK question being raised again because a stretch of Interstate in Arizona (the I-19 which runs north from the Mexican border to Tuscon) is about to be de-metricated (Green Valley News & Sun: I-19 losing kilometer signs).

So, we move back to the British problem. A thread was started on this subjects at one of my favourite haunts, SABRE (the Society for All British Road Enthusiasts) and once again there were comments that it's about time we got on with the job here... followed by another mentioning cost. I think it's time we put these costs into perspective.

First we'll look at the money collected by the government from the use of cars. According to various sources, the tax disk (Road Fund Licence, VED, whatever you want to call it) collected about £5.1 billion in the 2006/7 financial year. At the same time taxation from fuel collected £23.6 billion, so we have a total of £28.7 billion in the pot which, from a moral viewpoint, should be spent on tranport.

Next we look at road spending. Those of us who drive will know that road maintenance is clearly not a priority for the government or local authorities who seem to be more content at installing speed humps and cameras rather than filling in pot holes, resurfacing worn out roads or re-engineering  dangerous junctions, but in any case we do see that money is spent. The recent widening works on the M1 in Hertfordshire (junctions 6A to 10) apparently cost the taxpayer £300 million. 

In comparison, a 2006 estimate by the DfT to metricate our roads was placed at between £680-£760 million, twice the cost of that particular piece of widening works. Many people consider this estimate to be over-inflated since it based merely on adding up the cost of replacing road signs, many of which are replaced by regular maintenance cycles anyway. The UKMA estimated at the time that the actual cost would actually be nearer £80 million, this based on the methods used to metricate road signs in Canada and Ireland where this very method was used. Only conversion of speed limit signs actually need cost anything.

The main bulk of the conversion could be carried out at very little cost using the following simple plan.

1. Make the use of metric on ALL non-distance signs mandatory on all new signs (this would be in cases where metric is already permitted such as on height,width and length limit signs). After a 3-5 year period make imperial-only signs illegal, this would allow time to replace most under usual mantenence schedules and then patch the rest (patching HAS been used to cover metric-only and dual metric-imperial signs to imperial only in the past!). Ther should be no reason for anything other than inserts in road tax renewal letters explaining the rule change, even older drivers should by now understand how metres work.
2. Make the use of metres legal instead of yards and impose the same time limit for replacement of all signs through normal maintenence. At the same time ban the use of "m" to mean miles on all road signs... most of the signs where this is done are on motorways and trunk roads so it should be fairly easy for the DfT and/or Highways Agency to patch these signs either removing the "m" or, alternatively, changing distances to metres. On junction countdown signs for instance, "¼ m" would become "400 m", "½ m" would become "800 m", other distances in "thirds" would become multiples of "500 m", all the way up to "2000 m". An advertising campaign could be run alongside this to ensure motorists are not confused by the changeover... remembering that Brits are no less intelligent than the Canadians, the Irish, or any of the other nationalities who have already gobe through this.
3. Start to put up all new distance signs in km. Ideally new signs should be metric only, however there is some scope for putting up some dual-unit signs, perhaps on trunk roads and motorways, and then using metric-only signs in all other areas. Again, this would be done over a 3-5 year timescale. After this, all remaining signs could be patched over.

Some might argue that there would be a need for proper planning on distances, focus groups, etc. However in my view this would be totally unnecessary. At the present time there are already rules in place which allow for a 10% variation in accuracy (which means, perversely, that a sign in "yards" could merely be switched to "metres" without changing the actual number). Distances over (I believe) 2 miles are usually only shown in whole miles and the same rule could be applied to km... with distances below 3 km being shown in metres which would avoid confusion with "m" for miles on older signs. Rounding miles to the nearest km should present no problem for the people tasked with the job as it's simple mathematics.

Advertising campaigns would be necessary throughout this process, but that needn't cost much money... in 2001 the UK government spent £16.4 million  on advertising, while this was said to be larger than consumer giants Unilever and Procter & Gamble, it is still only a small amount compared to road tax and fuel tax revenues or other road-related spending.

This would just leave the speed limits... that I will leave for now.

Just one thought though... I've been out on the roads a lot this last two weeks and noticed that, more and more, new width and height restriction signs in many parts of the country seem to be predominantly imperial-only, even those used by Highways Agency contractors and after DfT advice changed to recomend dual units in all cases.

Clearly strong legislation is required. Whatever happened to the up-coming DfT consultation on road signs???