scholarly journals Development of Direct Models for Percent Time-Spent Following on Two-Lane Highways

2020 ◽  
Vol 6 ◽  
Author(s):  
Faisal Ahmed ◽  
Said M. Easa
Keyword(s):  
Percent Time ◽  
Percent Time Spent Following ◽  
Direct Models

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.

scholarly journals ESTIMACIÓN DEL NIVEL DE SERVICIO DE UN CARRIL LENTO

2016 ◽  
Author(s):  
Víctor Gabriel Valencia Alaix ◽  
Alfredo García García
Keyword(s):  
Travel Speed ◽  
Highway Safety ◽  
Design Model ◽  
Highway Capacity ◽  
Highway Capacity Manual ◽  
Percent Time ◽  
Safety Design ◽  
Percent Time Spent Following

La operación vehicular en una carretera convencional depende de la atención adecuada de los adelantamientos de los vehículos lentos por parte de los más rápidos; una alternativa es mediante la provisión de carriles auxiliares a lo largo de la vía antes de pasar a una carretera multicarril.El objetivo es calibrar el modelo de simulación TWOPAS y aplicarlo en una carretera convencional española para estimar y comparar el nivel de servicio estimado en ella y en un carril lento con el resultado del procedimiento del Highway Capacity Manual - HCM.Se observó la operación vehicular en una carretera convencional de España mediante el registro a través de cámaras de control dispuestas a lo largo de la carretera, y en el carril lento, de manera que sirvió para calibrar el modelo de microsimulación TWOPAS considerando parámetros operacionales del parque automotor y aplicándolo para estimar el nivel de servicio.Se aplicó el procedimiento del HCM para estimar el nivel de servicio en segmentos de carretera con carril lento para comparar sus resultados con los obtenidos en la simulación.El modelo de simulación usado fue el TWOPAS, inserto en el Traffic Analisys Module (TAM) del Interactive Highway Safety Design Model (IHSDM), cuyos resultados en términos de Percent Time Spent Following (PTSF), Average Travel Speed (ATS) y otros permite la evaluación operacional.Los resultados y conclusiones permiten valorar la utilidad del modelo, la correspondencia de la realidad operacional en carretera y la norma española y la conveniencia operacional del carril lento estudiado.DOI: http://dx.doi.org/10.4995/CIT2016.2016.4220

scholarly journals Adaptação do HCM2000 para análise da capacidade e do nível de serviço em rodovias de pista simples no Brasil

TRANSPORTES ◽  
2011 ◽  
Vol 19 (2) ◽  
pp. 66
Author(s):  
José Reynaldo Setti ◽  
José Elievam Bessa ◽  
Márcia Lika Mon-Ma ◽  
Cíntia Yumiko Egami
Keyword(s):  
Flow Rate ◽  
Travel Speed ◽  
Level Of Service ◽  
Research Projects ◽  
Rural Highways ◽  
Percent Time ◽  
Adjustment Factors ◽  
Percent Time Spent Following ◽  
The U.S

A meta deste trabalho foi descrever, de maneira prática, como aplicar uma adaptação do método do HCM2000 para análise da capacidade e do nível de serviço em rodovias de pista simples brasileiras. A adaptação proposta resulta de duas pesquisas que, basicamente, replicaram os procedimentos usados no desenvolvimento do método original do HCM, substituindo os dados obtidos em rodovias dos EUA e Canadá por dados coletados em dez trechos de rodovias brasileiras. Dessa forma, são apresentadas relações entre a taxa de fluxo, a velocidade média de viagem e a porcentagem de tempo seguindo em pelotões, além de tabelas com fatores de ajuste para condições não básicas. Podem ser avaliados segmentos longos e homogêneos, numa análise em sentido duplo ou em senti-do único, além de rampas específicas. Os resultados obtidos indicam que as estimativas dos níveis de serviço usando-se a adaptação do método do HCM2000 tendem a refletir melhor as reais condições operacionais das vi-as brasileiras de pista simples. ABSTRACTThe goal of this study was to describe, in a practical way, how to apply an adaptation of HCM2000 method for capacity and level of service analysis on two-lane rural highways. The proposed adaptation is the result of two research projects that basically replicated the procedures used for developing the original HCM method, while replacing the data collected on highways in the U.S. and Canada for data from ten sections of Brazilian high-ways. Thus, relationships between flow rate, average travel speed and percent time-spent-following are present-ed, as well as tables containing adjustment factors for situations differing from base conditions. It is possible to estimate the level of service of long homogeneous segments, considering one-way or two-way flows, as well as specific upgrades. The results indicate that the level of service estimates obtained with the use of the HCM2000 adaptation tend to reflect better the actual highway conditions.

Sign in / Sign up

Export Citation Format

Share Document