Legibility of Variable Message Signs for Drivers
| Autor: | Kai-Hsiang Chan, 詹凱翔 |
|---|---|
| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 99 Variable Message Signs (VMS) are programmable traffic management facilities. A variety of dynamic messages are conveyed to drivers through text or graphic symbols. However, there is no uniform requirement for the VMS in Taiwan, thus their setups are at the sole discretion of the traffic or road competent authorities. In addition, there is the lower age limit for obtaining a driver’s licenses, but there is no upper age limit for driving on roads. Therefore, this study aimed to explore the different age groups’ VMS legibility under different driving environments, different contents presented, and with different driving speeds. First of all, the 30 subjects in the pre-test consist of the middle-aged group and younger age group. The results show that the middle-aged group had to spend more time searching for targets. In addition, the content type of the VMS and the driving environment also affected the subjects’ degree of legibility and number of reading errors. For the contents designed in pure-text, more time was needed to understand them. In addition, in the driving environment during the day, there were more number of reading errors, and nearly half of the subjects were unable to finish reading the VMS contents at a visual angle comfortable to them. That is, they were unable to quickly and accurately read the various information, thus the VMS setup was in vain. When drivers can barely read them, traffic hazards are likely to result. Based on the pre-test results, literature reviews, and actual observation of the roads, the three improved signboard dimensions of 1.3m, 1.6m, and 1.9m were proposed for the validation experiment. Through the ANOVA analysis of the three factor areas, the results show that at the reading distance of 1.3m, the legibility was poorer, while the number of errors was higher, but with the three improved heights the subjects were able to finish reading the messages before the disappearance distance suggested in the literatures, and the number of errors was reduced. The findings in this study are expected to serve as a reference for future VMS signboard research and design applications. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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