[A1D08] TRB papers (help)

we have a paper that i need to get at least one more review on. unfortunately, i can't find anyone to review it. below is the abstract. the paper was passed to us by another committee and in my opinion should be lodged somewhere between whatever committee knows how loop detectors work and the statistics committee--like the expressway surveillance folks. but anyway we got it. if anyone want to take a crack at it let me ASAP. ==================== An Improved Travel-time Estimation Algorithm using Dual Loop Detectors This paper presents an algorithm for the off-line estimation of route-level travel times for uninterrupted traffic flow facilities, such as motorway corridors, based on time-series of traffic speed observations on the sections that constitute a route. The proposed method is an extension of an existing and widely used method known as the trajectory method. The novelty of the new method is the fact that trajectories are constructed based on the assumption of piecewise linear (and continuous at section boundaries) vehicle speeds rather than piecewise constant (and discontinuous at section boundaries) speeds. Based on these assumptions, mathematical expressions are derived that describe the trajectories within each section. These expressions can be used to replace their existing counterparts in the traditional trajectory methods. A comparison of the accuracy of the new method and the existing method has been carried out based on simulated data. This comparison shows that the RMSE value for the new method is about half the RMSE value for the existing method. After decomposing this RMSE error in a bias and a residual error, it turns out that the existing method significantly overestimates the travel time. However the largest part of the reduction of the RMSE value is still due to a reduction of the residual error. In other words: if both methods are corrected for their bias the new method performs significantly better.