Details:

Creators:
Paz, Alexander ; Molano-Paz, Victor Hugo
Paz, Alexander ; Molano-Paz, Victor Hugo Less -
Corporate Creators:
University of Nevada, Las Vegas. Transportation Research Center
Corporate Contributors:
Nevada. Dept. of Transportation ; University Transportation Centers Program (U.S.)
Nevada. Dept. of Transportation ; University Transportation Centers Program (U.S.) Less -
Subject/TRT Terms:
[+]
Algorithms Behavior Calibration Microscopic Traffic Flow Microsimulation Performance Measurement Saturation Flow Traffic Models Traffic Simulation Travel Patterns
Resource Type:
Tech Report
Geographical Coverage:
United States
Corporate Publisher:
University of Nevada, Las Vegas. Transportation Research Center
Abstract:
This study proposes a methodology to calibrate microscopic traffic flow simulation models.

The proposed methodology has the capability to calibrate simultaneously all the calibration

parameters as well as demand patterns for any network topology. These parameters include global and

local parameters as well as driver behavior and vehicle performance parameters; all based on multiple

performance measures, such as link counts and speeds. Demand patterns are included in the

calibration framework in terms of turning volumes. A Simultaneous Perturbation Stochastic

Approximation (SPSA) algorithm is proposed to search for the vector of the model’s parameters that

minimizes the difference between actual and simulated network states. Previous studies proposed

similar methodologies; however, only a small number of calibration parameters were considered, and

none of the demand values. Moreover, an extensive and a priori process was used in order to choose

the subset of parameters with the most potential impact.

In the proposed methodology, the simultaneous consideration of all model parameters and

multiple performance measures enables the determination of better estimates at a lower cost in terms

of a user’s effort. Issues associated with convergence and stability are reduced because the effects of

changing parameters are taken into consideration to adjust them slightly and simultaneously. The

simultaneous adjustment of all parameters results in a small number of evaluations of the objective

function. The experimental results illustrate the effectiveness and validity of this proposed

methodology. Three networks were calibrated with excellent results. The first network was an arterial

network with link counts and speeds used as performance measurements for calibration. The second

network included a combination of freeway ramps and arterials, with link counts used as performance

measurements.

Considering simultaneously arterials and freeways is a significant challenge because the two

models are different and their parameters are calibrated at the same time. This represents a higher

number of parameters, which increases the complexity of the optimization problem. A proper solution

from all feasible solutions becomes harder to find. The third network was an arterial network, with

time-dependent link counts and speed used as performance measurements. The same set of calibration

parameters was used in all experiments. All calibration parameters were constrained within reasonable

boundaries. Hence, the design and implementation of the proposed methodology enables the

calibration of generalized micro-simulation traffic flow simulation models.


Format:
PDF
Collection(s):
US Transportation Collection University Transportation Centers
Main Document Checksum:
[+]
urn:sha256:244b01d0e662ef84f5dc7dba8f8ed112a17f8d140da3d6f056af4d9cf234049c
Download URL:
https://rosap.ntl.bts.gov/view/dot/26887/dot_26887_DS1.pdf
File Type:

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