Poster presented at the 23rd PIARC World Road Congress in Paris, 2007.

1. The mean speed of the 10 fastest cars passing and
meeting caravans of road marking trucks in relation
to road width and the presence of lighted signs
(backtransformed mean±SE). The roads are classified as
narrow <10 m and broad >10 m.
0
20
40
60
80
100
120
Broad Narrow
Road width
Speed
(km/h)
Light off Light on
Median speed of vehicles passing and meeting a
caravan of road marking trucks in relation to road
width and the presence of lighted signs
(backtransformed mean±S.E.). The roads are
classified as narrow <10 m and broad >10 m.
0
20
40
60
80
100
Broad Narrow
Road width
Speed
(km/h)
Light off Light on
The proportion of vehicles passing and meeting
caravan of road marking trucks that are driving
dangerously fast (> 70 km/h in relation to road width
and the presence of lighted signs (backtransformed
mean±SE). The roads are classified as narrow <10 m
and broad >10 m.
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
Broad Narrow
Road width
Proportion
Light off Light on
Evaluation of method for reducing travel speed of cars
passing or meeting working trucks during painting of road
markings.
Some of the worst accidents at roadwork zones in
Sweden involve caravans of road marking vehicles. High
traffic speeds past roadworks is recognised as a frequent
causal factor. This study was aimed at evaluating the
traffic calming effect of a set of Variable Message Signs
(VMS), mounted on a slow-moving caravan of road
marking vehicles. The VMS displayed the maximum
recommended speed throughout the zone. The results
were evaluated by means of new small portable radar
equipment that surveyed the speed of vehicles both
passing and meeting the caravan.
The case results showed that without activating the VMS,
both the average and top speeds were very high, thereby
entailing an unacceptable risk. However, when the VMS
was activated, the average speed was reduced by 22
km/h on wide roads. Similarly, the mean speed of the ten
fastest vehicles was reduced by 16 km/h. Finally, the
percentage of vehicles driving at extremely
high/hazardous speeds (> 70 km/h) dropped from 62% to
12%, which is a relative reduction of 81%. As a result,
Swedish legislation is being reviewed with the intention to
legalise the use of this type of VMS on moving road work
vehicles.
TRAFFIC CALMING AT MOBILE ROADWORK ZONES:
USE OF VEHICLE-MOUNTED RADAR TO EVALUATE THE EFFECT OF VARIABLE
MESSAGE SIGNS (292)
F. Friberg, M. Persson, J. Granlund & Å. Johansson
Swedish Road Administration
vagverket@vv.se
Röda vägen 1, 781 87 Borlänge
+0046 243-119 119