Swedish vision zero experience.

The objective of this paper is to present the Swedish Vision Zero Experience concerning separating car traffic with cable barriers and upgrading traffic safety on existing 13 m roads using low cost measures. In 1998, the Director General of SNRA decided on a full-scale programme to improve traffic safety on six existing 13 m roads using low-cost measures, preferably within the existing right-of-way. The main alternative is the 2 + 1 solution with a separating cable barrier, preferably within the existing 13 m width. This solution was estimated to have a potential to prevent some 50% of all severe link accidents. Findings so far have been so successful that SNRA has decided to generally replace the old 13 m roads with the 2 + 1 solution. The main results and findings up to May 2001 are as follows: (1) Speed performance on 2 + 1 roads with cable barrier is the same, or even better than an ordinary semi-motorway at one directional flows up to 1400 v/h. The capacity is estimated to be about 1650 v/h in one direction, some 300 v/h less than for an ordinary 13 m road. (2) Emergency and tow agencies are complaining as their workload has increased. (3) The transition zones from 2 to 1 lane have performed well. The proportion of vehicles in the beginning of the zone is small. Drivers tend to handle the design of the transition zones in a cautious and responsible manner. (4) The traffic safety effect on severe accidents was expected to be high on 2 + 1 road with cable barrier. So far in eight objects total length there has not been any fatal and only 6 persons with severe injuries. This is about 60% less than on ordinary semi-motorways and supports the prediction at fatal and severe injuries can be reduced with up to 50%. (5) Median cable barrier crashes are very frequent but normally without person injuries. (6) Driver attitude surveys show that drivers attitude to roads with cable barrier have been changed in a positive direction. (7) The maintenance costs are increased with about 120 Thousand SEK (12000US$) per km per year. (Author/publisher)