Application of LiDAR and Connected Vehicle Data to Evaluate the Impact of Work Zone Geometry on Freeway Traffic Operations

Abstract

Extensive literature exists regarding recommendations for lane widths, merging tapers, and work zone geometry to provide safe and efficient traffic operations. However, it is often infeasible or unsafe for inspectors to check these geometric features in a freeway work zone. This paper discusses the integration of LiDAR (Light Detection And Ranging)-generated geometric data with connected vehicle speed data to evaluate the impact of work zone geometry on traffic operations. Connected vehicle speed data can be used at both a system-wide (statewide) or segment-level view to identify periods of congestion and queueing. Examples of regional trends, localized incidents, and recurring bottlenecks are shown in the data in this paper. A LiDAR-mounted vehicle was deployed to a variety of work zones where recurring bottlenecks were identified to collect geometric data. In total, 350 directional miles were covered, resulting in approximately 360 GB of data. Two case studies, where geometric anomalies were identified, are discussed in this paper: a short segment with a narrow lane width of 10–10.5 feet and a merging taper that was about 200 feet shorter than recommended by the Manual on Uniform Traffic Control Devices. In both case studies, these work zone features did not conform to project specifications but were difficult to assess safely by an inspector in the field because of the high volume of traffic. The paper concludes by recommending the use of connected vehicle data to systematically identify work zones with recurring congestion and the use of LiDAR to assess work zone geometrics.

Movement of Autonomous Vehicles in Work Zone Using New Pavement Marking: A New Approach

“…According to Fengxiang Qiao [4] the intelligent work zone system are developed combining the functions of detection, system monitoring, system commu- There are three aspects of LiDAR deployment [15]. First, all agencies apply highly reflective glass beads or elements to pavement marking to improve night visibility.…”

“…First, all agencies apply highly reflective glass beads or elements to pavement marking to improve night visibility. Well, maintain retroreflective marking provides very high contrast in LiDAR point cloud and can be easily extracted via automated processes [15]. Second, environmental conditions need to be considered when using LiDAR.…”

“…In one night time lane closure workers in reflective gear standing in front of floodlight were more visible in the Li-DAR point cloud than could be visibly observed by the driver. However, LiDAR performance is significantly degraded when there is precipitation [15]. Third, the speed at which mobile LiDAR travels affects the density of the data point cloud, slower speed will produce denser point cloud but may be less safe on high-speed facilities, such as freeway.…”

LiDAR-Based Mobile Mapping System for Lane Width Estimation in Work Zone

“…When a lane is narrow, it would result in a reduced roadway capacity, which would lead to traffic congestion and also, increase the probability of severe accidents. Moreover, the lane capacity in work zones is drastically less than that in non-work zone areas with the same lane width, as shown in Figure 1.1 (Mekker et al, 2018) Using mobile mapping systems (MMS) equipped with Light Detection and Ranging (LiDAR) units and cameras, geo-referenced point clouds and images can be collected rapidly in work zones without affecting traffic. Then, road characteristics can be derived from the acquired point cloud for risk assessment.…”

“…Next, the conceptual basis of LiDAR point positioning is discussed in Chapter 4. In Chapter 5, the proposed calibration procedure of a mobile mapping system comprising several spinning Figure 1.1 Summary of freeway capacity estimation for different scenarios (Mekker et al, 2018). multi-beam laser scanners (i.e., Velodyne laser scanners) and GNSS/INS unit is delivered.…”