Analyzing roadway work zone effects on vehicular flow in a freeway ring

Abstract

Roadway work zone forms as a result of traffic accidents or road maintenance. In this paper, to analyze roadway work zone effects on vehicular flow in a freeway ring, a macroscopic multi-lane traffic model is proposed, the model describes the mandatory net lane-changing rate just upstream the roadway work zone with a random number model based on golden section analysis, and the net-changing rate in normal road segment with a lane-changing time model. Assuming that the free flow speeds on lanes I–III are 120, 100 and 90[Formula: see text]km/h, respectively, with a numerical method of third-order accuracy, the model equations are solved numerically to simulate vehicular flows in a three-lane freeway ring with a roadway work zone with a total length of 160[Formula: see text]m and lane III completely banned. Numerical results show that the roadway work zone generates traffic shock when initial density normalized by jam density is around 0.18. While the ramp flows have little effect on mean travel time through the freeway ring road with a total length of 100[Formula: see text]km, but can cause observable deviation of the root mean square value of travel time.

Freeway work zone effects on vehicular fuel consumption explored by a four-lane model

“…For the vehicular flow shown schematically in Figure 1, the three-lane model of Huang et al 1 is extended to a four-lane model by changing the total lane number from 3 to 4 and assuming that the work zone has two completely blocked lanes. The four-lane model belongs to continuum type, macroscopic category, describes vehicular flow by partial differential equations from a phenomenological point of view.…”

“…Assume length scale is just the grid length l 0 , and velocity scale is v 0 as defined in Table 1, time scale t 0 should be t 0 = l 0 =v 0 . Normalize lane traffic density r l by jam density r m and lane traffic flow rate q l by q 0 = r m v 0 , use the definition u l = q l =r l , in the normal segment x 6 2 ½x wz1 , x wz2 , the model of Huang et al 1 can be extended for four-lane traffic flow with lane number l 2 f1, 2, 3, 4g in the following form:…”

“…Recently a three-lane continuum model was developed by Huang et al 1 The model describes the mandatory net lane-changing rate just upstream the roadway work zone with a random number model based on golden section analysis, and the net-changing rate in normal road segment with a lane-changing time model. This model was used to analyze roadway work zone effects on vehicular flow in a freeway ring.…”

“…Many traffic models were discussed including those mentioned recently by Huang et al 1 Cassidy and Rudjanakanoknad 2 pointed out that lane changing is a difficult phenomenon in traffic modeling. Patire and Cassidy 3 studied lane changing patterns of bane and benefit, unveiled a mechanism by which congestion forms on a three-lane, uphill expressway segment, and causes reductions in output flow, and found vehicular lane changing is key to the mechanism, particularly lane changing induced by speed disturbances that periodically arise in the expressways median and center lanes.…”

“…However, to ascertain the effects on vehicular flow on a four lane freeway with work zones, the three-lane model 1 should be extended. To explore the effects on vehicular fuel consumption from a freeway work which has a length of 100 m and occupies lanes III and IV, the extended traffic model equations are solved numerically by a method called WENO5–RK3 by Li et al’s 17 study.…”