Percent Time-Spent-Following as Performance Measure for Two-Lane Highways

2001 ◽  
Vol 1776 (1) ◽  
pp. 52-59 ◽  
Author(s):  
R. Tapio Luttinen
Keyword(s):  
Performance Measure ◽  
Percent Time ◽  
Percent Time Spent Following

scholarly journals PERCENT TIME-SPENT-FOLLOWING MODEL FOR SINGLE CARRIAGEWAY ROAD

2019 ◽  
Vol 81 (6) ◽  
Author(s):  
Lee Vien Leong ◽  
Shafida Azyanti Mohd Shafie ◽  
Wins Cott Goh
Keyword(s):  
Performance Indicator ◽  
Threshold Value ◽  
Video Camera ◽  
Performance Measure ◽  
Threshold Values ◽  
Heavy Vehicles ◽  
Percent Time ◽  
Indicator Analysis ◽  
And Performance ◽  
Percent Time Spent Following

 Percent time-spent following (PTSF) is an important parameter in determining level-of-service of a single carriageway road but the current performance measure adopted in Malaysia is based on volume over capacity (v/c) ratio. Therefore, this study aims to develop a new PTSF model that is suitable for single carriageway roads in Malaysia. Traffic flow at 32 sites in various states in Malaysia were recorded using CCTV and video camera. Image processing software was used to extract volume, speed and headway data. Surrogate measure which is the percentage of vehicles travelling with headway threshold values of 3.0 and 5.0 seconds were used in estimating PTSF in the field. Initially, the base PTSF (BPTSF) model was developed and subsequently used to develop six different PTSF models using headway threshold values of 3.0 and 5.0 seconds and different variables. Analyses and performance indicators showed that the model developed based on the headway threshold value of 5.0 seconds with the inclusion of percentage of no-passing zone, opposing flow rate and percentage of heavy vehicles is the best model. This model was determined as the best fit as it has the highest score of 15, which is the maximum score based on performance indicator analysis.

Review of Percent Time Spent Following (PTSF) as Performance Measure for Two-lane Highways

2013 ◽  
Vol 64 (1) ◽  
Author(s):  
Muttaka Na'iya Ibrahim ◽  
Othman Che Puan ◽  
Mushairry Mustaffar
Keyword(s):  
Empirical Studies ◽  
Measurement Model ◽  
Performance Measure ◽  
Highway Capacity ◽  
Highway Capacity Manual ◽  
Percent Time ◽  
Surrogate Measure ◽  
Analytical Procedures ◽  
Percent Time Spent Following ◽  
Related Measure

The Highway Capacity Manual (HCM) uses Percent Time Spent Following (PTSF) as key service measure for assessing the level of service of two-lane highways. However, the indicator is difficult to measure directly in the field. For this reason, its estimation to date has been based on analytical procedures using equations derived from simulations and field observations at representative location based on surrogate measure; as the percent of vehicles traveling with headway less than 3 seconds (3 s). Findings from empirical studies confirmed that the HCM analytical procedures used in estimating PTSF yield results that are inconsistent with the 3 s surrogate measure and mostly overestimate the indicator. This paper presents a review on the estimation of PTSF on two-lane highways and suggests probable approach to substantiate the application of the current practice. Further, the authors of this paper argued that the use of 3 s as surrogate for estimating PTSF based on field observation at a specific point may not represent the actual time spent following over a long segment of two-lane highway since PTSF is space related measure. Hence, the authors suggest the use of test vehicle approach over the highway segment to be evaluated to identify the variables that are required for the development of a representative PTSF measurement model. It is expected that this review and suggestion offered will contribute in advancing performance analysis of two-lane highways. 

Uncertainty in Operational Analysis of Two-Lane Highways

2002 ◽  
Vol 1802 (1) ◽  
pp. 105-114 ◽  
Author(s):  
R. Tapio Luttinen
Keyword(s):  
Input Data ◽  
Travel Speed ◽  
Level Of Service ◽  
Model Parameters ◽  
Highway Capacity ◽  
Highway Capacity Manual ◽  
Operational Analysis ◽  
Percent Time ◽  
Different Types ◽  
Percent Time Spent Following

The Highway Capacity Manual (HCM) 2000 provides methods to estimate performance measures and the level of service for different types of traffic facilities. Because neither the input data nor the model parameters are totally accurate, there is an element of uncertainty in the results. An analytical method was used to estimate the uncertainty in the service measures of two-lane highways. The input data and the model parameters were considered as random variables. The propagation of error through the arithmetic operations in the HCM 2000 methodology was estimated. Finally, the uncertainty in the average travel speed and percent time spent following was analyzed, and four approaches were considered to deal with uncertainty in the level of service.

Analysis on the Convection of Highway in Permafrost Regions

2012 ◽  
Vol 204-208 ◽  
pp. 1644-1647
Author(s):  
Xiao Yu Sun ◽  
Zhen Qing Wang ◽  
Hong Tao Xing ◽  
Yong Heng Tong
Keyword(s):  
Flow Characteristics ◽  
Theoretical Development ◽  
Construction Costs ◽  
Rural Highways ◽  
Percent Time ◽  
Traffic Volumes ◽  
Percent Time Spent Following ◽  
The Cost ◽  
Permafrost Regions ◽  
Key Parameter

The purpose of this study was to evaluate flow characteristics on two-lane rural highways and to develop criteria for highway widening The study is conducted on two tracks: theoretical development of delay models and use of a simulation model to estimate the effect of certain parameters on delay and percent-time-spent-following. Models of delay are presented, as are the regions in which the traffic is stable or unstable. It was also possible from the simulation to obtain the percent-time-spent-following, which is a key parameter in determining level-of-service on two-lane highways.The accrued delay over the usable life of a two-lane highway pavement, assumed to be 20 years, was discounted to present monetary value This was then compared to four typical construction costs for different terrain types. The threshold average daily traffic volumes were determined at the points where the present value of the accumulated delay was equal to the cost of constructing two more lanes. These threshold values can be used as criteria for widening a two-lane highway and converting it into a four-lane facility. Additional criteria, based on percent-time-spent-following, are also presented.

Evaluation of Models to Estimate Percent Time Spent Following on Two-Lane Highways

2017 ◽  
Vol 143 (5) ◽  
pp. 04017010 ◽  
Author(s):  
José Elievam Bessa ◽  
José Reynaldo Setti ◽  
Scott S. Washburn
Keyword(s):  
Percent Time ◽  
Percent Time Spent Following

Field Evaluation of Highway Capacity Manual 2000 Analysis Procedures for Two-Lane Highways

2002 ◽  
Vol 1802 (1) ◽  
pp. 125-132 ◽  
Author(s):  
Michael P. Dixon ◽  
Satya Sai Kumar Sarepali ◽  
Kevin Allen Young
Keyword(s):  
Simulation Model ◽  
Field Data ◽  
Field Evaluation ◽  
Analysis Procedure ◽  
Highway Capacity ◽  
Highway Capacity Manual ◽  
Percent Time ◽  
Percent Time Spent Following ◽  
Northern Idaho ◽  
Rural Highway

Highway Capacity Manual (HCM) 2000 two-lane rural highway directional, two-way, and passing-lane analysis procedures based on field data and simulation were evaluated. Detailed field data were collected from two highway sections in northern Idaho, one with and one without passing lanes. The TWOPAS simulation model was used to provide additional insights. Particular attention was given to the differences in estimates for percent time spent following (PTSF) produced by the twoway and directional analysis procedures. It was found that the two-way analysis procedure was more accurate, although both procedures produced estimates that were too high. The passing-lane analysis procedure was also evaluated, and the HCM 2000 procedure was found to be conservative in its estimates of PTSF reductions due to a passing lane.

Sign in / Sign up

Export Citation Format

Share Document