Lettering
14. Although standard direction signs at present make use of upper case (capital) letters only, the experimental traffic signs erected on the Preston By-Pass employ lower case lettering with initial capitals in accordance with the provisional recommendation made in our interim report. This is the practice both in the U.S.A. and in Germany. We made it clear in that report, however, that we could make no final recommendation as to the detailing of the alphabet to be used in motorway signs until the legibility and general suitability of this provisional lettering had been assessed under working conditions.
15. As a result of our inspection of the signs on the Preston By- Pass we have considered some minor modifications of the letter forms and now recommend the adoption of the alphabet which appears at Appendix II to this report. The new lettering, with its correct spacing, has also been used in the signs illustrated in Appendix IV. The redesigning of the letter forms has resulted in a slight reduction in the overall size of the signs without loss of legibility.
16. The use of lower case lettering at Preston was on the whole well received— indeed, those representative organisations that have commented on it have been almost unanimously in favour. There has, however, been some criticism of it in the correspondence columns of The Times, where it has been suggested that if upper case letters were used and the information appearing on the signs were better arranged the overall size of the signs could be much reduced with no loss of legibility; it was also suggested that further tests should be carried out on the form of lettering to be used in motorway signs.
17. Our own observations tend to show that the distinctive shape that words acquire when lower case lettering with initial capitals is used helps recognition and reduces the time taken to pick out the relevant part of the total message, and there is expert American evidence[1] that on signs of comparable size a greater degree of legibility can be achieved by the use of lower rather than upper case lettering. This evidence, however, relates to signs on which only one name appears; tests which our own Road Research Laboratory have carried out on signs with more than one name suggest that where margins and vertical spacing are reduced to the bare minimum, so as to obtain maximum legibility without regard to considerations of appearance, this advantage does not apply. We feel, however, that in designing a traffic sign regard must be paid to the space around the lettering as well as to the lettering itself, and that a sign that completely filled the space available would be so unattractive as to be quite unacceptable.
18. This being so, we are concerned with only a very slight difference in area of sign, as between upper and lower case lettering, for the same degree of legibility. Our choice has therefore been finally determined by a wider field of considerations. We have a preference for lower case lettering, which we feel accords better than upper case with the general design of the motorways. Moreover, we consider it likely that an increasingly cosmopolitan motoring public will encounter more and more lower case lettering on signs of all kinds and will come to expect it,
- ↑ T. W. Forbes, K. Moskowitz and G. Morgan: 'A comparison of lower case and capital letters for highway signs ' (Proc. Highway Res. Bd., 1950, 30, 355–73).
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