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Abstract
The paper reviews several strategies of restricting or separating trucks from the regular traffic
stream. Typical truck restriction policies focus on leftmost lanes restriction, which has been shown
by several studies to have some advantages. However, those studies clearly show that vehicle queue
lengths in the vicinity of critical merging areas increase significantly as the percentage of trucks
increases. Therefore, this study examines a different policy—one which investigates traffic efficiency
gained by restricting heavy truck traffic in one direction—in this case, westbound on Highway 1 in
Israel—during afternoon peak hours. Similar policies of utilizing a specific vehicle category (e.g.
passenger cars or trucks) in different daily time periods or physical separation of homogenous
traffic of passenger cars in the inner lanes and mixed traffic in the outer lanes, were recommended
in Italian motorways and in New Jersey Turnpike dual-dual freeways respectively.
Highway 1 is a freeway connecting Jerusalem and Tel Aviv that passes by Ben-Gurion
International Airport. The major objective of this study is to estimate the benefit of restricting truck
traffic in the traffic stream according to three traffic-flow parameters: average travel time, total travel
time, and average traffic speed. Analysis of the results, which consider the significant differences
of 30-minute time period samples (“before-after” truck restriction), shows that prohibiting trucks
in all lanes in one direction during the peak afternoon period of 16:00-18:00 improved all three
traffic flow parameters by 8%-12%. Generally a steep grade from which truck traffic is banned is
correlated with an improvement in traffic flow. In our case, Highway 1 road segments 1 and 2 and
4, which have steep grades (longitudinal grades), incorporated the most significant improvements
in the traffic stream parameters examined.