Nonparametric Modeling of Vehicle-Type-Specific Headway Distribution in Freeway Work Zones

Abstract

This paper presents a vehicle-type-specific headway distribution analysis in a freeway work zone. The goal of this paper is to provide a vehicle-type-specific model with different time periods using empirical work-zone data from highway I-91 in Greenfield, MA. A nonparametric approach with a Gaussian kernel is used to describe the vehicle-type-specific headway distribution in a freeway work zone. No assumption is required on how the headways should be distributed for nonparametric methods. The vehicles are classified into Car, Van, and Truck based on a FHWA vehicle-type classification scheme. Statistical tests indicate nonparametric distribution with Gaussian kernel outperforms the lognormal distribution in statistical sense according to the