In 2000, an experiment was conducted with "speed limit reminder" signs. On some sections of main rural roads, new signs were installed which reminded the drivers of the actual speed limits on those roads. The experiment was performed, following a mutual decision by the Road Safety Authority and the Public Works Department of the Ministry of Transport, which was stimulated, inter alia, by repeated claims by Israeli drivers, caught for speeding, that they did not know the actual speed limits on a specific road section. In general, in Israeli practice, speed limits are stated by Traffic law for several categories of roads, and as long as the limit stays valid for a road section, no sign is available. Only in the case of a speed limit on a road section, which is higher or lower than the one stated by the law for this category of roads, a special instructive sign is installed on the roadside. As it was stated by drivers and some representatives of the road authorities, such a situation seemed confusing and possibly contributing to a high rate of speed limit violations in rural areas. In order to evaluate the influence of the new signs on driving speeds, two rounds of field measurements accompanied the signs' introduction, before and after the signs' installation. The measurements were automatic and performed at six representative sites, three on a single-carriageway and three on dual-carriageway roads. In each group, two sites were of treatment (i.e. situated on a section with new signs installed) and the third one was a control site. At each site, the speeds were measured in both travel directions. The study analysed the data of the speed measurement surveys, comparing the "after" relative to "before" measures such as average speeds, 85-percentile speeds, the rate of violating the speed limit, the rate of violating the level of speed limit plus 10 kph, the rate of driving at extremely high speeds (110-120 kph). The analysis was performed separately for all free-flow hours and for night free-flow hours only. The results showed that both on single-carriageway and dual-carriageway roads, no change or a mixed trend was observed in most speed measures considered, following the signs' introduction. This, in comparison with positive trends in speeds seen at the single-carriageway control site and a mixed trend seen at the dual-carriageway control site. Overall, it was concluded that speed limit reminder signs have a negligible and not systematic influence on actual driving speeds on rural roads. For the covering abstract see ITRD E123193.
Abstract