Milled rumble strips in combination with the centre line could be a way to
improve traffic safety and to explore the concept of selfexplanatory roads as
a counter measure. The aim of the study was to evaluate whether a centre line
in combination with a milled rumble strip helps to improve driver behaviour
with the possible result of fewer accidents, especially head-on accidents.
The evaluation mainly dealt with the rumble strip as a self explanatory
counter measure and only indirectly considered forgiving road aspects e.g.
warning by the rumble strip in the event of a lane deviation caused by driver
fatigue or distraction. A before-after study was initiated in August 2003.
Three different methods were used; measures of speed and lateral position for
traffic flow in four positions on the road, observations of overtaking
behaviour and finally road side interviews. The result showed that milled
rumble strips in combination with the centre line definitely have en effect
on car drivers. They reduced their speed by 1.8 kilometres per hour and they
drove 5 centimetres closer to the edge line. Both changes in speed and
lateral position were significant at the 5% level. There were no significant
effects on truck drivers' choice of speed or position. Furthermore there was
no significant difference in overtaking behaviour. The rumble strips were
favourably received by drivers; 76% answered that milled rumble strips at
centre line would make them feel more secure about that no driver will
inadvertently drive into their lane; 83% answered that milled rumble strips
will make them feel secure about that they are not about to leave the lane
without being aware of this; 88% of the respondents thought milled rumble
strips at the centre line will increase traffic safety.
Linköping: VTI. VTI rapport 508 , 2005.
Swedish, Sweden, Rumble strip, Median, Carriageway marking, Accident prevention, Before and after study, Speed, Lateral, Location, Traffic lane