In Finland, a benefit-cost analysis supported the deployment of weather information controlled variable speed limits on highly trafficked road segments.
The benefit-cost analysis covered a period of 20 years and assumed an annual two percent increase in traffic and an annual five percent decrease in personal injury accidents. The safety data were derived from previous research. Ancillary impacts on pollution and noise costs were assumed marginal and were not included in the analysis. The system costs input into the analysis included construction and maintenance costs derived from recently built systems and evaluated at the 2004 level.
The implementation plan was designed to accommodate two types of facilities: motorways and dual carriageways (divided highways), and single carriageways (roadways with no physical separation). The following data excerpted from table 2 of the report show the combinations of technologies deployed.
Speed limit signs
Combined information and warning signs
Traffic monitoring stations
Road weather stations
Traffic monitoring cameras
|Motorways and dual carriageways||6 units /graded intersection. If the spacing between intersections is longer than 5km, speed limit repeater signs are required (4 units).||One for each carriageway for each intersection spacing||Every graded intersection spacing has one traffic monitoring station||One for every 15km||One for each graded intersection|
|Single carriageways||4 units /intersection. If the spacing between intersections is longer than 5km, speed limit repeater signs are required (2 units).||One for every other intersection spacing||One for each 20km||One for each 15km||One for each 20km|
Overall, the results of the benefit-cost analysis were favorable for deployments along highly trafficked road segments. Starting (low-end) benefit-to-cost ratios ranged from 1.1:1 to 1.9:1. Ratios increased for scenarios where higher safety benefits were assumed and control policies allowed for higher speed limits.
Country-Wide Variable Speed Limits?
Author: Schirokoff, A., P. Rama, and A. Tuomainen
Published By: Paper presented at the XIII International Road Weather Conference (SIRWEC) 2006
Source Date: 25 March 2006
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Intelligent Transportation Systems > Road Weather Management > Traffic Control > Variable Speed Limits
Intelligent Transportation Systems > Road Weather Management > Surveillance, Monitoring, & Prediction > Atmospheric Conditions
Intelligent Transportation Systems > Freeway Management > Surveillance > Traffic
Intelligent Transportation Systems > Road Weather Management > Surveillance, Monitoring, & Prediction > Pavement Conditions
Intelligent Transportation Systems > Road Weather Management > Information Dissemination > Dynamic Message Signs
VSL, RWIS, ESS, Environmental Sensor Station, RWIS Station, road monitoring, weather station, environmental sensing station, CCTV, closed circuit television cameras, sensors, vehicle detector, traffic detection, traffic monitoring, congestion monitoring, DMS, CMS, VMS, Changeable Message Signs, Variable Message Signs