This research was a "scan team" effort jointly sponsored by the Federal Highway Administration (FHWA), the American Association of State Highway and Transportation Officials (AASHTO), and the Transportation Research Board (TRB). During a two-week period in May 1998, the team visited with transportation officials in Gothenburg, Sweden; Frankfurt, Cologne, and Bonn, Germany; Paris, France; and London and Birmingham, England to identify noteworthy practices and technologies that may have value in the United States.
A traffic management system of detection, lane control, variable message signs, and variable speed limits is used in Gotherberg, Sweden. Called Motorway Traffic Management it used in the Lundby tunnel and utilizes a system of loop detectors and video cameras to measure traffic volumes and speeds, for classifying vehicles, and for incident detection. Information is provided to motorist through a series of variable message signs. Lane control and variable speed limits are used to control traffic flow. Similar systems have provided a variety of documented benefits. In Amsterdam, Netherlands the system reportedly reduced the "overall accident rate" by 23 percent, reduced the "serious accident rate" by 35 percent, and reduced the "secondary accident rate" by 46 percent. In Germany, the accident rate fell by 20 percent in areas where variable speed limit signs and lane control signals were used to warn drivers of congested conditions on the A5 autobahn between Bad Homburg and Frankfurt/West. On a comparable section of autobahn without control, accidents increased by 10 percent in the same time period.