Limits...
Intelligent advisory speed limit dedication in highway using VANET.

Jalooli A, Shaghaghi E, Jabbarpour MR, Noor RM, Yeo H, Jung JJ - ScientificWorldJournal (2014)

Bottom Line: The IASLD provides the advisory speed limit for each vehicle exclusively based on the vehicle's characteristics including the vehicle type, size, and safety capabilities as well as traffic and weather conditions.The proposed approach takes advantage of vehicular ad hoc network (VANET) to accelerate its performance, in the way that simulation results demonstrate the reduction of incident detection time up to 31.2% in comparison with traditional VSL strategy.The simulation results similarly indicate the improvement of traffic flow efficiency, occupancy, and travel time in different conditions.

View Article: PubMed Central - PubMed

Affiliation: Department of Computer System and Technology, University of Malaya, 50603 Kuala Lumpur, Malaysia.

ABSTRACT
Variable speed limits (VSLs) as a mean for enhancing road traffic safety are studied for decades to modify the speed limit based on the prevailing road circumstances. In this study the pros and cons of VSL systems and their effects on traffic controlling efficiency are summarized. Despite the potential effectiveness of utilizing VSLs, we have witnessed that the effectiveness of this system is impacted by factors such as VSL control strategy used and the level of driver compliance. Hence, the proposed approach called Intelligent Advisory Speed Limit Dedication (IASLD) as the novel VSL control strategy which considers the driver compliance aims to improve the traffic flow and occupancy of vehicles in addition to amelioration of vehicle's travel times. The IASLD provides the advisory speed limit for each vehicle exclusively based on the vehicle's characteristics including the vehicle type, size, and safety capabilities as well as traffic and weather conditions. The proposed approach takes advantage of vehicular ad hoc network (VANET) to accelerate its performance, in the way that simulation results demonstrate the reduction of incident detection time up to 31.2% in comparison with traditional VSL strategy. The simulation results similarly indicate the improvement of traffic flow efficiency, occupancy, and travel time in different conditions.

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Related in: MedlinePlus

(a) Impact of IASLD on occupancy of highway segments which are affected by traffic congestion. (b) Alteration of traffic congestions in IASLD.
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fig19: (a) Impact of IASLD on occupancy of highway segments which are affected by traffic congestion. (b) Alteration of traffic congestions in IASLD.

Mentions: For evaluation of IASLD and VSL impacts on controlling the traffic congestions caused by growth in number of vehicles travelling in specific location of the highway, we have simulated the scenario of injecting the large number of vehicles to the entrance E23 prior to station 90 under the dry condition, whilst the average volume of the vehicles in station 90 has been 1430. Figures 19(a) and 20(a) illustrate, respectively, the IASLD and VSL impacts, on occupancy of highway segments which are affected by the traffic congestion. Thus, the alterations of occupancy parameters from the station 40 to station 90, in IASLD and VSL, from the initiation time of congestion detection until the end of simulation time are analyzed. In IASLD, the detection has been initiated (time 0) by perceiving the light congestion in station 90. Afterwards, there has been further detection of light congestion and moderate congestion in station 80 at the times 60 and 100, respectively. On the other hand, in VSL, by increasing the occupancy of vehicles more than the defined threshold in the station 90, and afterwards exceeding the volume, the new speed limits are applied, respectively, in times 0 and 140, to this station. The absence of integrated speed buffering along the consecutive segments in VSL caused the applying of new speed limits in stations 80, 70, and 60 to postpone to later time intervals at which the exceeding of occupancy and volume parameters is detected. Hence, every station has experienced a considerable rise in occupancy of vehicles before moderating the traffic flow. The comparison of IASLD and VSL in Figures 19(a) and 20(a) illuminates that IASLD had 8.1%, 7.9%, 20.8%, 28.9%, 26.8%, and 23.4 % improvements in reduction of occupancy, respectively, in stations 90, 80, 70, 60, and 50 rather than VSL after 320 seconds from first congestion detection. The represented contour maps in Figures 19(b) and 20(b) clarify the alterations of traffic congestions from the distance 2000 to 4500 meters of the highway during the 320 seconds from the detection of aforementioned congestion in IASLD and VSL approach, respectively. The depicted variation of density and occupancy in Figure 19(b) prominently indicates the influence of using gradual speed buffering directly on the traffic controlling of vehicles in IASLD, in the way that the density of traffic in stations 90, 80, 70,and 60 after 320 seconds from applying the speed limit policy is 34%, 18.1%, 19.2%, and 19.8% diminished, respectively. On the other side, Figure 20(b) manifests nonexistence of integrated traffic controlling, which correspondingly caused the VSL confronts with scattering of traffic congestion in prior stations by lapse of time.


Intelligent advisory speed limit dedication in highway using VANET.

Jalooli A, Shaghaghi E, Jabbarpour MR, Noor RM, Yeo H, Jung JJ - ScientificWorldJournal (2014)

(a) Impact of IASLD on occupancy of highway segments which are affected by traffic congestion. (b) Alteration of traffic congestions in IASLD.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4066950&req=5

fig19: (a) Impact of IASLD on occupancy of highway segments which are affected by traffic congestion. (b) Alteration of traffic congestions in IASLD.
Mentions: For evaluation of IASLD and VSL impacts on controlling the traffic congestions caused by growth in number of vehicles travelling in specific location of the highway, we have simulated the scenario of injecting the large number of vehicles to the entrance E23 prior to station 90 under the dry condition, whilst the average volume of the vehicles in station 90 has been 1430. Figures 19(a) and 20(a) illustrate, respectively, the IASLD and VSL impacts, on occupancy of highway segments which are affected by the traffic congestion. Thus, the alterations of occupancy parameters from the station 40 to station 90, in IASLD and VSL, from the initiation time of congestion detection until the end of simulation time are analyzed. In IASLD, the detection has been initiated (time 0) by perceiving the light congestion in station 90. Afterwards, there has been further detection of light congestion and moderate congestion in station 80 at the times 60 and 100, respectively. On the other hand, in VSL, by increasing the occupancy of vehicles more than the defined threshold in the station 90, and afterwards exceeding the volume, the new speed limits are applied, respectively, in times 0 and 140, to this station. The absence of integrated speed buffering along the consecutive segments in VSL caused the applying of new speed limits in stations 80, 70, and 60 to postpone to later time intervals at which the exceeding of occupancy and volume parameters is detected. Hence, every station has experienced a considerable rise in occupancy of vehicles before moderating the traffic flow. The comparison of IASLD and VSL in Figures 19(a) and 20(a) illuminates that IASLD had 8.1%, 7.9%, 20.8%, 28.9%, 26.8%, and 23.4 % improvements in reduction of occupancy, respectively, in stations 90, 80, 70, 60, and 50 rather than VSL after 320 seconds from first congestion detection. The represented contour maps in Figures 19(b) and 20(b) clarify the alterations of traffic congestions from the distance 2000 to 4500 meters of the highway during the 320 seconds from the detection of aforementioned congestion in IASLD and VSL approach, respectively. The depicted variation of density and occupancy in Figure 19(b) prominently indicates the influence of using gradual speed buffering directly on the traffic controlling of vehicles in IASLD, in the way that the density of traffic in stations 90, 80, 70,and 60 after 320 seconds from applying the speed limit policy is 34%, 18.1%, 19.2%, and 19.8% diminished, respectively. On the other side, Figure 20(b) manifests nonexistence of integrated traffic controlling, which correspondingly caused the VSL confronts with scattering of traffic congestion in prior stations by lapse of time.

Bottom Line: The IASLD provides the advisory speed limit for each vehicle exclusively based on the vehicle's characteristics including the vehicle type, size, and safety capabilities as well as traffic and weather conditions.The proposed approach takes advantage of vehicular ad hoc network (VANET) to accelerate its performance, in the way that simulation results demonstrate the reduction of incident detection time up to 31.2% in comparison with traditional VSL strategy.The simulation results similarly indicate the improvement of traffic flow efficiency, occupancy, and travel time in different conditions.

View Article: PubMed Central - PubMed

Affiliation: Department of Computer System and Technology, University of Malaya, 50603 Kuala Lumpur, Malaysia.

ABSTRACT
Variable speed limits (VSLs) as a mean for enhancing road traffic safety are studied for decades to modify the speed limit based on the prevailing road circumstances. In this study the pros and cons of VSL systems and their effects on traffic controlling efficiency are summarized. Despite the potential effectiveness of utilizing VSLs, we have witnessed that the effectiveness of this system is impacted by factors such as VSL control strategy used and the level of driver compliance. Hence, the proposed approach called Intelligent Advisory Speed Limit Dedication (IASLD) as the novel VSL control strategy which considers the driver compliance aims to improve the traffic flow and occupancy of vehicles in addition to amelioration of vehicle's travel times. The IASLD provides the advisory speed limit for each vehicle exclusively based on the vehicle's characteristics including the vehicle type, size, and safety capabilities as well as traffic and weather conditions. The proposed approach takes advantage of vehicular ad hoc network (VANET) to accelerate its performance, in the way that simulation results demonstrate the reduction of incident detection time up to 31.2% in comparison with traditional VSL strategy. The simulation results similarly indicate the improvement of traffic flow efficiency, occupancy, and travel time in different conditions.

Show MeSH
Related in: MedlinePlus