The VTI has taken part in the evaluation of the first test of ramp metering system in Sweden. Since the end of 1994, a system has been in use on the E18 at Taeby just north of Stockholm. VTI has taken part in the evaluation by measuring speeds and traffic flows at a number of points on the motorway and the ramp, both when the system was active in April and when it was temporarily shut down for evaluation in May. During April and May, the VTI conducted fuel consumption studies on the motorway and ramp. By analysing the speed measurements upstream and downstream of the interchange, it has been possible to estimate the time savings. In money it means a net saving of SEK 115,000 per year. The fuel consumption year. The fuel consumption measurements resulted in a more uniform speed profile and somewhat higher speed in queue situations. For both left and right hand lanes on the main road and ramp, the measurements gave a calculated reduction in fuel consumption of 110 litres and a reduction in carbon dioxide emissions of 269 kg per day. In one year, this gives a saving of just over SEK 70,000. Together with the time costs, the first year's savings will be approximately SEK 185,000, to be seen in relation to installation costs of SEK 400,000 plus the maintenance costs for the system. (A)
Abstract