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Trans. Planning Journal
| Title | PASSENGER CAR EQUIVALENTS OF LARGE VEHICLES ON FREEWAY UPGRADE SEGMENTS |
|---|---|
| Author | Pin-Yi Tseng、Kuan-Nan Chen |
| Summary | The analysis methodology of level-of-service on freeway segments usually converted real traffic flow rate to equivalent passenger-car flow by constant passenger-car-equivalent (PCE). However, it did not reflect the effect of grade,length of grade and percentage of heavy vehicle on upgrade segments. This study employed the TGS model, developed by the Institute of Transportation, to simulate the traffic condition and estimate heavy vehicle’s PCE on freeway upgrade segments. On the basis of the simulation results, this study found that average speed decreased with the increase of grade, length of grade and percentage of heavy vehicles. In addition, the PCE increased with the increase of grade and length of grade, but decreased with the increase of percentage of heavy vehicles. The PCE approximated 2.0 when the grade below 2%. Finally,this study suggested using TGS model to simulate and estimate capacity or level-of-service when grade greater than 2%, rather than convert directly the mixed traffic flow into the equivalent passenger cars by a constant PCE. |
| Vol. | 45 |
| No. | 3 |
| Page | 165 |
| Year | 2016 |
| Month | 9 |
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