Calibrating and Validating Deterministic Traffic Models

2005 ◽  
Vol 1920 (1) ◽  
pp. 95-105 ◽  
Author(s):  
Rui Miguel Batista Paulo ◽  
Jiong Lin ◽  
Nagui M. Rouphail ◽  
Jerome Sacks
Keyword(s):  
Model Parameters ◽  
Validation Process ◽  
Highway Capacity ◽  
Traffic Models ◽  
Highway Capacity Manual ◽  
Calibration And Validation ◽  
Model Predictions ◽  
Statistical Issues ◽  
Estimation Of Model Parameters

Calibration and validation of traffic models are processes that depend on field data that are often limited but are essential for determination of inputs to the model and assessment of its reliability. Quantification and systematization of the calibration and validation process expose statistical issues inherent in the use of such data. Formalization of the calibration and validation process naturally leads to the use of Bayesian methodology for assessment of uncertainties in model predictions that arise from a multiplicity of sources, especially statistical variability in estimation and calibration of the input parameters and model discrepancy. The general problem was elucidated in an earlier paper; this paper carries out the full calibration and validation process in the context of a widely used deterministic traffic model, namely, the Highway Capacity Manual model for control delay at signalized intersection approaches. In particular, the reliability of the model was assessed through quantification of the uncertainty in the estimation of model parameters, predictions of model delay, and predictions obtained by adjusting the data used in the model. While the methods are described in a specific context, they can be used generally but are inhibited at times by computational burdens that must be overcome.

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.

scholarly journals Calibration and Validation Indonesian Highway Capacity Manual 1997 Model

2020 ◽  
Vol 852 ◽  
pp. 012023
Author(s):  
Budi Yulianto ◽  
Setiono ◽  
Rizki Dewayani Putri ◽  
Stevani Tia Pratisca ◽  
Felix Fernando Hartono
Keyword(s):  
Highway Capacity ◽  
Highway Capacity Manual ◽  
Calibration And Validation

scholarly journals Evaluation passenger car unit for motorcycle in Indonesia Highway Capacity Manual (Case study: Bandung and Semarang)

2018 ◽  
Vol 181 ◽  
pp. 06006
Author(s):  
Najid
Keyword(s):  
Traffic Density ◽  
Heavy Vehicles ◽  
Highway Capacity ◽  
Passenger Car ◽  
Highway Capacity Manual ◽  
Traffic Conditions ◽  
A Value ◽  
Passenger Car Unit ◽  
Set Up

Value of Passenger Car Unit or commonly known as PCU value is a value that is given to any vehicle that is classified into heavy vehicles, light vehicles (passenger car) and motorcycles. The value of passenger car unit on Indonesia Highway Capacity Manual (IHCM) set up in 1997 is based on a study conducted from 1980-1990 in several cities in Indonesia At the time of the study, the traffic conditions are very different to the current traffic conditions. That affects of difference traffic conditions are the composition of traffic, traffic regulations, traffic density, traffic discipline and the presence of mass transit, so that the results of traffic analysis do not always correspond to reality as there are anomalies in the determination of the level of road service (Najid, 2014). As well the incompatibility of the capacity value which is considered due to the incompatibility value of Passenger Car Units (PCU). Evaluation PCU become very important to get the value of traffic parameters into compliance with actually occur. In accordance with the traffic density is higher actually, then it is necessary to study for evaluation against PCU current value and the need to approach or to get the value of PCU more in line with current traffic conditions. Data collected at two cities, those are Bandung and Semarang. Based on analysis found PCU’s value that got from survey have difference but not all significantly with PCU value in IHCM.

scholarly journals Capacity and Delay Estimation for Roundabouts Using Conflict Theory

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Zhaowei Qu ◽  
Yuzhou Duan ◽  
Hongyu Hu ◽  
Xianmin Song
Keyword(s):  
Queuing Theory ◽  
High Volume ◽  
Conflict Theory ◽  
Model Parameters ◽  
Delay Model ◽  
Highway Capacity ◽  
Highway Capacity Manual ◽  
Traffic Characteristics ◽  
Capacity Model ◽  
Proposed Model

To estimate the capacity of roundabouts more accurately, the priority rank of each stream is determined through the classification technique given in the Highway Capacity Manual 2010 (HCM2010), which is based on macroscopical analysis of the relationship between entry flow and circulating flow. Then a conflict matrix is established using the additive conflict flow method and by considering the impacts of traffic characteristics and limited priority with high volume. Correspondingly, the conflict relationships of streams are built using probability theory. Furthermore, the entry capacity model of roundabouts is built, and sensitivity analysis is conducted on the model parameters. Finally, the entrance delay model is derived using queuing theory, and the proposed capacity model is compared with the model proposed by Wu and that in the HCM2010. The results show that the capacity calculated by the proposed model is lower than the others for an A-type roundabout, while it is basically consistent with the estimated values from HCM2010 for a B-type roundabout.

Determining the capacity of the Canadian trans-mountain highway system

1976 ◽  
Vol 3 (3) ◽  
pp. 355-371
Author(s):  
John F. Morrall ◽  
Neville Cameron ◽  
Al Werner
Keyword(s):  
Highway Capacity ◽  
Passenger Car ◽  
Highway Capacity Manual ◽  
Recreational Vehicles ◽  
Improper Use ◽  
Adjustment Factors ◽  
Highway Planning ◽  
Design Hourly Volume ◽  
Selection Of

Trans-mountain highway capacity is sensitive to the percentage of recreational vehicles in the traffic stream, the manner in which passenger car equivalents for recreational vehicles are used in capacity computations, terrain classification, and the choice of design hourly volume. The sensitivity of capacity to these factors is demonstrated for the trans-mountain portion of the Trans-Canada highway which is a two-lane highway, characterized in many locations by long steep grades. This particular highway has a high percentage of recreational vehicles during summer months. The Highway Capacity Manual does not make any provision for the effect of such vehicles and previous highway planning studies have used the adjustment factors for trucks and buses to estimate their effect. Neglecting the effect of recreational vehicles and/or improper use of their passenger car equivalents in capacity computations can result in serious errors in the determination of highway capacity especially in mountainous areas. Further research is required in the areas of terrain definition, selection of design hourly volume, and the present concept of level of service.

Meaning of actual capacity of freeways and its estimation

2010 ◽  
Vol 37 (1) ◽  
pp. 77-87 ◽  
Author(s):  
Shy Bassan ◽  
Abishai Polus
Keyword(s):  
Curve Fitting ◽  
Flow Characteristics ◽  
Time Interval ◽  
Unstable Flow ◽  
Highway Capacity ◽  
Highway Capacity Manual ◽  
Freeway Capacity ◽  
Capacity Estimates ◽  
Equal Density

The flow on urban and suburban freeways is characterized typically by high densities, occupancies, and frequent breakdowns, particularly when the volume approaches capacity. This creates unstable flow conditions, resulting in recurrent as well as random congestion. The purpose of this study was twofold: (1) to develop models for evaluating flow characteristics on a busy suburban freeway, specifically speed versus flow and flow versus occupancy; (2) to understand the meaning of capacity by evaluating the actual capacity of a freeway section. The data were collected on Highway 1 in Israel and on Interstate 66 in Virginia, USA. Previous observations showed that both freeways operated at a saturated-flow condition almost daily and that breakdowns of the stream occurred often, though not daily. The paper presents a concept that suggests that freeway capacity is an actual-site specific term. This capacity can change frequently in space and time, depending on the section geometry, the time interval, the prevailing traffic and environmental conditions, and driving behavior. Determination of a representative value of actual capacity for level-of-service or planning analyses is suggested, based on one of three methods: parabolic curve-fitting for free-flow, dense congested stable (DCS) flow, and breakdown-flow data; the intersection of the best-fit stable-flow parabola and the equal-density adjusted line; and curve fitting of one-regime models to flow-occupancy data. Also included is a comparison with the 2000 Highway capacity manual (HCM) models and with capacity estimates from other studies. The results showed similar values of actual capacity estimates for the three methods.

scholarly journals Analysis of calculating level of service for pedestrians

2021 ◽  
Vol 2021 (1) ◽  
pp. 50-59
Author(s):  
Vsevolod Prykhodko ◽  
◽  
Ihor Vikovych ◽  
Keyword(s):  
Level Of Service ◽  
Signal Delay ◽  
Highway Capacity ◽  
Pedestrian Movement ◽  
Highway Capacity Manual ◽  
Road Users ◽  
Method Of Determination ◽  
Significant Probability ◽  
Main Factors

In this paper, several methods of the assessment of pedestrian objects operation based on the level of service are reviewed. Today, there is a problem that should be assessed, particularly how pedestrian paths respond the level of service. Assessment of this level is the most widespread method of determination the objects` quality that relate to the pedestrian operations. Places, where a significant probability of conflict between different flows and their users, are often called intersections. Moreover, on such intersections, particularly with complex road conditions and on which the movement of cyclists, cars, and different vehicles is present, road users face with complicated situations when every of them should be sure in his safety and forecast further actions and decisions of other road users. The most widespread and generally accepted methods of assessment of level of service on pedestrian path, particularly: Highway capacity manual 2000 method, Australian method, method of the trip quality, Landice model and common approach analysis. Vehicles, signal delay, and interaction of pedestrians and cyclists were determined as the main factors that have impact on the level of service of pedestrians at the intersections. Analysis of different methods in the paper allows assessing and identifying the level of service determining the characteristics that could help in solving the questions concerning the comfort of pedestrian movement. In the range of these methods, the principles of vehicles movement and interaction with pedestrians are also reviewed. Other methods relate more to the design of the objects of pedestrian environment than factual movement of pedestrians. To form the whole understanding of the methodology of determination of the level of service of pedestrian objects, we should analyze and compare the values, obtained by different methods.

scholarly journals Evaluation of the Quality of Service of Pedestrian Flows on a Signalized Intersections

2019 ◽  
Vol 65 (2) ◽  
pp. 37-42
Author(s):  
Vuk Bogdanović ◽  
Nemanja Garunović ◽  
Valentina Basarić ◽  
Jelena Mitrović Simić
Keyword(s):  
Quality Of Service ◽  
Signalized Intersections ◽  
Highway Capacity ◽  
Local Conditions ◽  
Highway Capacity Manual ◽  
Traffic Conditions ◽  
Novi Sad ◽  
First Time

In 5th edition of Highway Capacity Manual (2010) the methodology for evaluating the quality of service provided to pedestrians traveling through a signalized intersection first time was shown. The same methodology has been retained in the latest edition of the aforementioned manual. Provided methodology include determination of the key parameters for evaluation the quality of service of pedestrian flows on signalized intersections. In this paper mentioned methodology was shown through the short procedural steps. In order to verify the possibility of applying this procedure in local conditions, an analysis of traffic conditions at an intersection in Novi Sad was performed as an example.

Alternative Regression Model Structure for the HCM-6 Equal-Capacity Passenger Car Equivalency Methodology

2021 ◽  
pp. 036119812199582
Author(s):  
Antonio Hurtado-Beltran ◽  
Laurence R. Rilett
Keyword(s):  
Regression Models ◽  
New Technologies ◽  
Complex Model ◽  
Model Parameters ◽  
Model Structure ◽  
Highway Capacity ◽  
Passenger Car ◽  
Highway Capacity Manual ◽  
Traffic Conditions ◽  
Equal Capacity

In the current version of the Highway Capacity Manual (HCM-6), equal-capacity passenger car equivalencies (EC-PCEs) are used to account for the effect of trucks for capacity analyses. The EC-PCEs for freeway segments were estimated using a microsimulation-based methodology where the capacities of the mixed-traffic and car-only flow scenarios were modeled. A nonlinear regression (NLR) model was used to develop capacity adjustment factor (CAF) models using the microsimulation data as input. The NLR model has a complex model structure and includes 15 model parameters. It is argued in this paper that simpler regression models could provide comparable results. This would allow CAF and EC-PCE equations to be used directly in the HCM-6 rather than tables. It would also allow for the development of new regression models for exploring new technologies such as connected and automated vehicles (CAVs). The objective of this paper was to develop alternative and simpler regression models of CAFs needed to derive the EC-PCE values in the HCM-6 methodology for freeway and multilane highway segments. It was found that simpler regression models provided similar results as those obtained with the current NLR model. Additionally, it was found that the current NLR model may not be adequate for analyzing CAV traffic conditions. If the HCM-6 EC-PCE methodology is expected to be used to analyze traffic conditions beyond the scope of the HCM-6, it is important to perform a deeper assessment of the form and error of the regression models used in fitting the simulated and estimated data.

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