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[EN] Traditionally traffic demand models require as input the impedance of a demand with respect to the network supply; mode choice or departure choice for example, take into account the travel time for each option. Bearing this in mind, the main criticism of using static models to evaluate travel times is that the estimated travel time could diverge considerably because these models have no capacity constraints. On the other hand, dynamic models, such as mesoscopic models, have a level of detail that is sometimes unnecessarily high for the final requirements. The Quasi-dynamic model developed in Aimsun could contribute to a more realistic estimate of the travel time while avoiding the need for a full dynamic model. This paper presents the integration of a Quasi-dynamic model inside the integrated framework of Aimsun and evaluates a comparison of all models in terms of travel time estimation. The evaluation is performed using real networks validated with real data sets.

[EN] Traditionally traffic demand models require as input the impedance of a demand with respect to the network supply; mode choice or departure choice for example, take into account the travel time for each option. Bearing this in mind, the main criticism of using static models to evaluate travel times is that the estimated travel time could diverge considerably because these models have no capacity constraints. On the other hand, dynamic models, such as mesoscopic models, have a level of detail that is sometimes unnecessarily high for the final requirements. The Quasi-dynamic model developed in Aimsun could contribute to a more realistic estimate of the travel time while avoiding the need for a full dynamic model. This paper presents the integration of a Quasi-dynamic model inside the integrated framework of Aimsun and evaluates a comparison of all models in terms of travel time estimation. The evaluation is performed using real networks validated with real data sets.

[EN] Traditionally traffic demand models require as input the impedance of a demand with respect to the network supply; mode choice or departure choice for example, take into account the travel time for each option. Bearing this in mind, the main criticism of using static models to evaluate travel times is that the estimated travel time could diverge considerably because these models have no capacity constraints. On the other hand, dynamic models, such as mesoscopic models, have a level of detail that is sometimes unnecessarily high for the final requirements. The Quasi-dynamic model developed in Aimsun could contribute to a more realistic estimate of the travel time while avoiding the need for a full dynamic model. This paper presents the integration of a Quasi-dynamic model inside the integrated framework of Aimsun and evaluates a comparison of all models in terms of travel time estimation. The evaluation is performed using real networks validated with real data sets.

[EN] Traditionally traffic demand models require as input the impedance of a demand with respect to the network supply; mode choice or departure choice for example, take into account the travel time for each option. Bearing this in mind, the main criticism of using static models to evaluate travel times is that the estimated travel time could diverge considerably because these models have no capacity constraints. On the other hand, dynamic models, such as mesoscopic models, have a level of detail that is sometimes unnecessarily high for the final requirements. The Quasi-dynamic model developed in Aimsun could contribute to a more realistic estimate of the travel time while avoiding the need for a full dynamic model. This paper presents the integration of a Quasi-dynamic model inside the integrated framework of Aimsun and evaluates a comparison of all models in terms of travel time estimation. The evaluation is performed using real networks validated with real data sets.

[EN] Traditionally traffic demand models require as input the impedance of a demand with respect to the network supply; mode choice or departure choice for example, take into account the travel time for each option. Bearing this in mind, the main criticism of using static models to evaluate travel times is that the estimated travel time could diverge considerably because these models have no capacity constraints. On the other hand, dynamic models, such as mesoscopic models, have a level of detail that is sometimes unnecessarily high for the final requirements. The Quasi-dynamic model developed in Aimsun could contribute to a more realistic estimate of the travel time while avoiding the need for a full dynamic model. This paper presents the integration of a Quasi-dynamic model inside the integrated framework of Aimsun and evaluates a comparison of all models in terms of travel time estimation. The evaluation is performed using real networks validated with real data sets.

Passing zones are provided to improve operational efficiency of two-lane highways where passes can be performed safely. Minimum passing zone lengths of 120 m were established in MUTCD and Green Book, although some studies indicate a potential need to increase them. However, no changes have been recommended pending further research on the safety of short passing zones. The objective of this study is to develop design and marking criteria for minimum passing zone lengths that consider traffic operational efficiency and safety. In the first part of this study, a traffic microsimulation was carried out with Aimsun software. The calibration and validation included the observation of 1,750 passing maneuvers in Spain. The results indicate that passing zones shorter than 250 m add very little to operational efficiency. In the second part of the study, a reliability analysis was applied. It quantified the probability that a passing maneuver was completed beyond the end of the passing zone (noncompliant passing maneuvers). Afterwards, the number of non-compliant passing maneuvers was calculated. Traffic flow as well as passing zone length were contributing factors.. Findings from the analysis indicate that the minimum passing zone length should be increased to a minimum of 275 m, for high traffic volumes, 300 m for medium traffic volumes and 350 m for low traffic volumes. From this length, the number of non-compliant passing maneuvers decreases. The marginal increase in the minimum length of passing zones can potentially improve safety without significantly reducing the operational efficiency. The results can be directly used by practitioners to establish the minimum passing zone length based on the range of hourly volumes and the level of risk willing to assume.

Microsimulation is a useful tool to analyze traffic operation. On two-lane highways, the complexity of passing and the interaction with oncoming traffic requires specific models. This study focused on the development of a passing desire, decision and execution model. Results of the observation of 1752 maneuvers on 10 rural roads in Spain were used for this development. The model incorporated the effect of new factors such as available sight distance, delay and remaining travel time until the end of the highway segment. Outputs of the model were compared to observed data: firstly, individual passing maneuvers; secondly, traffic flow, percent followers and number of passing maneuvers in four single passing zones with two different traffic levels. The model was validated in four alternative passing zones

Passing zones are provided to improve operational efficiency of two-lane highways where passes can be performed safely. Minimum passing zone lengths of 120 m were established in MUTCD and Green Book, although some studies indicate a potential need to increase them. However, no changes have been recommended pending further research on the safety of short passing zones. The objective of this study is to develop design and marking criteria for minimum passing zone lengths that consider traffic operational efficiency and safety. In the first part of this study, a traffic microsimulation was carried out with Aimsun software. The calibration and validation included the observation of 1,750 passing maneuvers in Spain. The results indicate that passing zones shorter than 250 m add very little to operational efficiency. In the second part of the study, a reliability analysis was applied. It quantified the probability that a passing maneuver was completed beyond the end of the passing zone (noncompliant passing maneuvers). Afterwards, the number of non-compliant passing maneuvers was calculated. Traffic flow as well as passing zone length were contributing factors.. Findings from the analysis indicate that the minimum passing zone length should be increased to a minimum of 275 m, for high traffic volumes, 300 m for medium traffic volumes and 350 m for low traffic volumes. From this length, the number of non-compliant passing maneuvers decreases. The marginal increase in the minimum length of passing zones can potentially improve safety without significantly reducing the operational efficiency. The results can be directly used by practitioners to establish the minimum passing zone length based on the range of hourly volumes and the level of risk willing to assume.

Microsimulation is a useful tool to analyze traffic operation. On two-lane highways, the complexity of passing and the interaction with oncoming traffic requires specific models. This study focused on the development of a passing desire, decision and execution model. Results of the observation of 1752 maneuvers on 10 rural roads in Spain were used for this development. The model incorporated the effect of new factors such as available sight distance, delay and remaining travel time until the end of the highway segment. Outputs of the model were compared to observed data: firstly, individual passing maneuvers; secondly, traffic flow, percent followers and number of passing maneuvers in four single passing zones with two different traffic levels. The model was validated in four alternative passing zones