Reading Speed to be Used for Highway Signs and Traffic Marking in Indonesia

The standard highway sign and traffic marking in Indonesia are adopted from mainly those of the U.S. Department of Transportation, the Manual of Uniform Traffic Control Devices, from England’s Road Research Laboratory and from India’s Indian Road Congress, which are all based on English language. For Indonesia, further studies are still needed to obtain the more appropriate letter dimension for highway sign and traffic marking, considering that similar words for highway sign in Indonesian language are generally much longer than those of the English version. This means highway user in Indonesia need longer time to read the sign along the roads so that the dimension of lettering and words should not be the same with in English version. From the previous studies, the reading speed was found to be 2 syllables per second and the letter dimension as function of clear-reading distance were given for letter with height-to width ratio H/B=4/3 and letter thickness t = 1/6 H. This study is the repeated effort to re-investigate the reading speed of letter in Indonesian language. The types of letter are the upper case (Capital letter) and lower case. A total of 40 variations of letter dimension are applied to hundreds of respondents. The results suggested that the average speed of reading letters in Indonesian language is 2 syllables per second and the results will be proposed to enhance traffic signs in Indonesia.