Sensitivity Analysis of Speed Limit, Truck Lane Restrictions, and Data Aggregation Level on the HCM-6 Passenger Car Equivalent Estimation Methodology for Western U.S. Conditions

Jianan Zhou, Laurence R Rilett, Elizabeth Jones

Research output: Contribution to journalArticle

Abstract

In the 2016 Highway Capacity Manual (HCM-6), the impact of trucks on freeway operations is measured by passenger car equivalents (PCEs). PCEs are estimated by the equal capacity methodology. The HCM-6 PCE values are based on the assumptions that passenger cars and trucks travel at the same free-flow speed, that they travel on freeways with three lanes per direction, and that they travel in traffic with no more than 25% trucks. On Interstate 80 in western Nebraska, it is observed that the interaction of high truck percentages and large speed differences between passenger cars and trucks may result in moving bottlenecks. It was hypothesized that the current HCM-6 PCEs may be not appropriate for these conditions. A companion paper showed this was true and that the major cause was speed differentials between trucks and passenger cars. In essence, when slow-moving trucks pass each other they create moving bottlenecks, which results in increased PCE values. This paper is an extension to a companion paper and examines a number of issues related to estimation of PCEs. The paper examines the effect of speed limit, truck passing restrictions, and data aggregation interval on PCEs. The results show that: (i) if a higher speed limit is implemented, trucks will affect the passenger cars more severely; (ii) if truck passing is restricted by lane restrictions, the negative impacts of trucks on passenger car operation may be mitigated; and (iii) using a longer data aggregation interval results in lower PCE values, all else being equal.

Original languageEnglish (US)
JournalTransportation Research Record
DOIs
StatePublished - Jan 1 2019

Fingerprint

Passenger cars
Trucks
Sensitivity analysis
Agglomeration
Highway systems

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Mechanical Engineering

Cite this

@article{5d0a220ad6624d728f6e42f35399fb60,
title = "Sensitivity Analysis of Speed Limit, Truck Lane Restrictions, and Data Aggregation Level on the HCM-6 Passenger Car Equivalent Estimation Methodology for Western U.S. Conditions",
abstract = "In the 2016 Highway Capacity Manual (HCM-6), the impact of trucks on freeway operations is measured by passenger car equivalents (PCEs). PCEs are estimated by the equal capacity methodology. The HCM-6 PCE values are based on the assumptions that passenger cars and trucks travel at the same free-flow speed, that they travel on freeways with three lanes per direction, and that they travel in traffic with no more than 25{\%} trucks. On Interstate 80 in western Nebraska, it is observed that the interaction of high truck percentages and large speed differences between passenger cars and trucks may result in moving bottlenecks. It was hypothesized that the current HCM-6 PCEs may be not appropriate for these conditions. A companion paper showed this was true and that the major cause was speed differentials between trucks and passenger cars. In essence, when slow-moving trucks pass each other they create moving bottlenecks, which results in increased PCE values. This paper is an extension to a companion paper and examines a number of issues related to estimation of PCEs. The paper examines the effect of speed limit, truck passing restrictions, and data aggregation interval on PCEs. The results show that: (i) if a higher speed limit is implemented, trucks will affect the passenger cars more severely; (ii) if truck passing is restricted by lane restrictions, the negative impacts of trucks on passenger car operation may be mitigated; and (iii) using a longer data aggregation interval results in lower PCE values, all else being equal.",
author = "Jianan Zhou and Rilett, {Laurence R} and Elizabeth Jones",
year = "2019",
month = "1",
day = "1",
doi = "10.1177/0361198119851451",
language = "English (US)",
journal = "Transportation Research Record",
issn = "0361-1981",
publisher = "US National Research Council",

}

TY - JOUR

T1 - Sensitivity Analysis of Speed Limit, Truck Lane Restrictions, and Data Aggregation Level on the HCM-6 Passenger Car Equivalent Estimation Methodology for Western U.S. Conditions

AU - Zhou, Jianan

AU - Rilett, Laurence R

AU - Jones, Elizabeth

PY - 2019/1/1

Y1 - 2019/1/1

N2 - In the 2016 Highway Capacity Manual (HCM-6), the impact of trucks on freeway operations is measured by passenger car equivalents (PCEs). PCEs are estimated by the equal capacity methodology. The HCM-6 PCE values are based on the assumptions that passenger cars and trucks travel at the same free-flow speed, that they travel on freeways with three lanes per direction, and that they travel in traffic with no more than 25% trucks. On Interstate 80 in western Nebraska, it is observed that the interaction of high truck percentages and large speed differences between passenger cars and trucks may result in moving bottlenecks. It was hypothesized that the current HCM-6 PCEs may be not appropriate for these conditions. A companion paper showed this was true and that the major cause was speed differentials between trucks and passenger cars. In essence, when slow-moving trucks pass each other they create moving bottlenecks, which results in increased PCE values. This paper is an extension to a companion paper and examines a number of issues related to estimation of PCEs. The paper examines the effect of speed limit, truck passing restrictions, and data aggregation interval on PCEs. The results show that: (i) if a higher speed limit is implemented, trucks will affect the passenger cars more severely; (ii) if truck passing is restricted by lane restrictions, the negative impacts of trucks on passenger car operation may be mitigated; and (iii) using a longer data aggregation interval results in lower PCE values, all else being equal.

AB - In the 2016 Highway Capacity Manual (HCM-6), the impact of trucks on freeway operations is measured by passenger car equivalents (PCEs). PCEs are estimated by the equal capacity methodology. The HCM-6 PCE values are based on the assumptions that passenger cars and trucks travel at the same free-flow speed, that they travel on freeways with three lanes per direction, and that they travel in traffic with no more than 25% trucks. On Interstate 80 in western Nebraska, it is observed that the interaction of high truck percentages and large speed differences between passenger cars and trucks may result in moving bottlenecks. It was hypothesized that the current HCM-6 PCEs may be not appropriate for these conditions. A companion paper showed this was true and that the major cause was speed differentials between trucks and passenger cars. In essence, when slow-moving trucks pass each other they create moving bottlenecks, which results in increased PCE values. This paper is an extension to a companion paper and examines a number of issues related to estimation of PCEs. The paper examines the effect of speed limit, truck passing restrictions, and data aggregation interval on PCEs. The results show that: (i) if a higher speed limit is implemented, trucks will affect the passenger cars more severely; (ii) if truck passing is restricted by lane restrictions, the negative impacts of trucks on passenger car operation may be mitigated; and (iii) using a longer data aggregation interval results in lower PCE values, all else being equal.

UR - http://www.scopus.com/inward/record.url?scp=85067924267&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85067924267&partnerID=8YFLogxK

U2 - 10.1177/0361198119851451

DO - 10.1177/0361198119851451

M3 - Article

JO - Transportation Research Record

JF - Transportation Research Record

SN - 0361-1981

ER -