The large number of signs on British roads was becoming a problem: there were so many that they were in danger of being ignored. In response, a committee was appointed in 1919 to consider and report on traffic signs. The committee's report, which was used to issue another Circular to local authorities in 1921, suggested the extension of the signing system specified in 1904, with more warning and regulatory signs specified.
In addition to the warning and regulatory sign system, the directional signing was given a good going over too. The roads were being classified and numbered at this time, and it was decided to make the public aware of these numbers, rather than keeping them for offical use only. Thus it was necessary to incorporate the road numbers on directional signs. To this end, fingerposts were standardised with place names in 3-inch high black block capitals on a white background. `Class I' roads were indicated by a black `A' and a number on a white background, and `Class II' roads were indicated by a white `B' and number on a black background.
Here is an example of a fingerpost, with road numbers on each `arm'. This picture was taken from the DoT's History of Traffic Signs brochure. Note that this was not an actual sign: the A749 is nowhere near Gloucestershire!
This was all fine and dandy, but highway authorities were still not obliged to use these signs, only strongly recommended. Variants were still being produced, and supplemented by the AA's and RAC's signs.
Yet another Circular was issued in 1930, still not obligatory. This introduced advance direction signs: cars were capable of travelling so fast as to need to brake sharply when the driver realised he had reached a junction, and needed to make a decision. These new signs (which had worded legends, eg `TURN RIGHT', and arrows) helped give drivers advance warning of a junction. More warning signs were introduced (for example the `steam engine' level crossing sign in the table below) and the distinctive STOP sign made its first appearance, although with a more wordy explanation of what the driver was required to do!
Yet another committee was set up to review the signing system in 1931; this reported back in 1933, and finally specified some recommendations which were legally enforceable. There were no major changes to the existing warning signs - the table below shows a selection of the plates (which were mounted beneath hollow red triangles).
| Sign meaning | Design | Sign meaning | Design | |
|---|---|---|---|---|
| Level crossing (no gates) | |
Level crossing (gates) | |
|
| Crossroads | |
Double bend | |
|
| Steep hill | |
Hump bridge ahead | |
|
| Low bridge ahead | |
Road narrows | |
|
| School | |
Side road | |
|
| 'T' junction | |
Traffic signals | |
|
| Give way | |
Halt/Stop | |
However, directional signing was overhauled yet again. The existing system, which consisted largely of fingerposts and wordy advance direction signs (such as `TURN LEFT FOR LONDON'), was no longer appropriate for faster traffic on the `A' and `B' roads. The signs were still black and white, with `A' roads black-on-white and `B' roads white-on-black, but there were a few changes:
 |
This is an example of a route confirmation sign, placed just after a junction to reassure drivers of the route they are on. This would have been in South East London, and means that by following this (unclassified) road, drivers could reach the A2, A20 and A21. |
 |
This is a `map'-type advance direction sign, erected just before a junction. Notice that the numbers now have more emphasis than the destinations. |
Surprisingly, despite these new regulations, the AA and RAC were still allowed to put up their own signs. These were of the same format as the 1933 Regulations signs, but with the addition of an AA or RAC badge.