01475381

Component

Long-span road bridges are governed by congested traffic rather than free-flowing conditions. During congestion, heavy vehicles can get quite close to each other, thus giving potential critical loading events for the bridge. In this paper, the effects of a system capable of warning truck drivers when the gap falls below a certain threshold are investigated. The effects are studied both in terms of increase in traffic disruption and reduction in loading. Ideally, the minimum distance between trucks should be adjusted for the site-specific traffic features and for the load the bridge is able to carry safely. Doing so, it will be possible to allow for future increase in truck weight regulations and/or heavy traffic volumes, by adjusting the control gap value. Importantly, the proposed system does not presume any restriction to the truck weight. By contrast, the system is meant to be an alternative way of limiting the load on long-span bridges by keeping the trucks apart, rather than by limiting the truck weight. The introduction of such a gap control system is studied by means of micro-simulation. The car-following model used here has been shown able to replicate many observed congestion patterns. Results show that the introduction of the gap control system does not significantly disrupt the traffic further. On the other hand, having only 10% of trucks complying with the gap control device beneficially reduces the total traffic loading by about 10%. When most trucks are compliant, nearly 50% reduction in the total load can be attained.

This paper was sponsored by TRB committee AT055 Truck Size and Weight.

01470560

13-1045

English

15p

2013

Transportation Research Board 92nd Annual Meeting

Digital/other

Figures; References; Tables

Car following; Design load; Heavy vehicles; Long span bridges; Microsimulation; Traffic control; Traffic loads; Vehicle spacing; Vehicle weight

Bridges and other structures; Highways; Motor Carriers; Operations and Traffic Management; I24: Design of Bridges and Retaining Walls; I73: Traffic Control

Transportation Research Board Annual Meeting 2013 Paper #13-1045

TRIS, TRB, ATRI

Feb 5 2013 12:18PM