01663926

Component

Numerous curve speed models have been developed for purposes such as predicting driver behavior, evaluating roadway design consistency, and setting curve advisory speeds. With any model development efforts, questions can be raised about the transferability of the model between geographic regions. It is desirable to develop speed prediction models that can be used to predict vehicle speeds across different regions, as these models can then form the basis for consistent roadway analysis and evaluation methods. However, speed model validation and especially calibration are expensive tasks because of the need to collect field data. The main objective of this paper is to present a validation of speed prediction models for horizontal curves using the SHRP2 database. For this purpose, four two-lane rural highway sections from the State of Indiana were selected where each section includes multiple horizontal curves. Roadway design characteristics were used to predict the speed at the midpoint of each curve based on models that were previously calibrated using Texas data. Actual vehicle speeds at each curve were then computed and compared with the predicted speed using the models in the literature. The results of the analysis suggest that the predicted speed from the Texas model provides an unbiased estimate of observed curve midpoint speeds in Indiana, and can provide good estimates of speeds at the beginning and ending of each curve with minor adjustment. The successful use of the SHRP2 database for model validation shows that this database can facilitate similar efforts in additional states.

This paper was sponsored by TRB committee AHB65 Standing Committee on Operational Effects of Geometrics.

18-04564

English

0000-0002-4592-9118

6p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

Figures; References; Tables

Highway curves; Mathematical prediction; Operating speed; Rural highways; Traffic data; Traffic models; Two lane highways; Validation

SHRP2 Naturalistic Driving Study

Indiana; Texas

Highways; Operations and Traffic Management; Planning and Forecasting

Transportation Research Board Annual Meeting 2018 Paper #18-04564

TRIS, TRB, ATRI

Jan 8 2018 11:07AM