Peter Martin - Academia.edu (original) (raw)

Papers by Peter Martin

Utah Department of …, 2003

… of Utah Traffic Lab. Final report, 2003

ARPN journal of engineering and applied sciences, 2011

The regional travel demand models are generally macroscopic in nature and do not include traffic ... more The regional travel demand models are generally macroscopic in nature and do not include traffic controls in the traffic assignment process. In travel demand models, the road capacities are kept fixed within the functional classification of roadways and free-flow-speeds are adjusted to accommodate the impacts of traffic controls and traffic operations. Part of the reason this approach is adopted in travel demand models is there macroscopic application, where the focus is extensively on the region wide results for transportation planning. While there are advantages in using this approach, the cost is usually paid in “lost capacity on projects” due to the absence of traffic operations in modeling; more precisely the absence of traffic controls tend to present partially skewed output from the travel models. Combined Traffic Assignment and Control models can address this issue by including the impacts of traffic controls in the modeling process. This paper evaluates the benefits of comb...

This paper evaluates impact of various I-15 reconstruction closure scenarios on the travelers in ... more This paper evaluates impact of various I-15 reconstruction closure scenarios on the travelers in Ogden area. The purpose of the research was to investigate impact of the scenarios and facilitate decision about future maintenance of traffic during the reconstruction. The original Wasatch Front Regional Council (WFRC) transportation planning model was converted from the TP+ software to the VISUM software. The VISUM model of the whole WFRC area was then calibrated and validated. Coefficient of determination between modeled and observed traffic volumes was 0.78. The model was then reduced, by partial network generation process in VISIM, to the Ogden area. Another set of calibration and validation was performed. The coefficient of determination has improved to 0.88. Twenty one reconstruction closure scenarios were developed in consultation with Utah Department of Transportation (UDOT) project managers. Traffic assignments were executed for each scenario for five diurnal periods. Measures...

Journal of Transport & Health, 2017

Background: Binational metropolitan regions consist of two or more different municipalities from ... more Background: Binational metropolitan regions consist of two or more different municipalities from two different countries connected by Ports-of-Entry (POEs). The El Paso-Ciudad Juarez binational metropolitan region has a population of approximately 2.5 million. Patients suffering from certain life-threatening conditions are frequently emergency-transported from Ciudad Juarez to a hospital in El Paso to receive specialized medical care. This research evaluated current ambulance cross-border operation protocols and practices followed in the El Paso-Ciudad Juarez region to transport these patients. Methods: This research was conducted in two stages. In the first stage, researchers conducted an extensive literature review to identify ambulance cross-border operation protocols currently in place worldwide. In the second phase, researchers used a series of meetings with agencies and organizations involved in the medical emergency transportation process in the El Paso-Ciudad Juarez region to characterize the problem and document the processes and protocols used by these agencies. The agencies included Mexican ambulance operators, U.S. Customs and Border Protection (CBP), and the El Paso Fire Department (EPFD). Results: Mexican ambulances transport patients to one of the POEs that connect Ciudad Juarez with El Paso. Once the Mexican ambulance arrives at the border, it has to wait in line with the rest of the passenger vehicles. As border officials realize an ambulance is approaching the border, they divert traffic so the ambulance can reach the CBP inspection booth as soon as possible. Then, officers quickly check the patient's documentation and call EPFD. The Mexican ambulance is then directed to a CBP secondary inspection facility so the patient is transferred to the EPFD ambulance. Finally, the patient is transported from the inspection facility to the hospital by the EPFD ambulance, and the Mexican ambulance returns to Mexico. The process involves multiple entities from both countries and one patient transfer. Conclusions: There is no formally agreed upon protocol to expedite ambulance cross-border operations between agencies and organizations on both sides of the border in the El Paso-Ciudad Juarez region. Each entity follows its own informal and independent operation protocol to the best of its ability. Therefore, the total transport time for patients that need to be emergency-transported from Ciudad Juarez to a hospital in El Paso to receive medical care can often exceed three hours. An improvement of the transportation time subsequently may impact the clinical outcome of these patients. The situation is similar in other binational metropolitan areas along the U.S.-Mexico border.

Transportation Research Procedia, 2016

The HCM2010 freeway facilities methodology offers a supplemental computational engine FREEVAL, wh... more The HCM2010 freeway facilities methodology offers a supplemental computational engine FREEVAL, which is a macroscopic/mesoscopic tool. It enables users to implement HCM-based freeway analysis quickly. Vissim is a microscopic simulation tool that enables users to model realworld conditions with high level of accuracy. One of the commonly used performance measures for freeway assessment is the Level-of-Service (LOS). The HCM freeway facility methodology uses density to estimate LOS. However, density is calculated differently in FREEVAL and Vissim, and comparing the estimated LOSs between the two may lead to invalid conclusions. The aim of this paper is to address a gap in the literature by comparing and contrasting the methodologies behind the two tools and by offering explanation and discussion of their outputs in terms of density and LOS. The study covers three major HCM freeway segment types (basic, on-ramp, and weaving) in undersaturated conditions. The assessment reveals that both tools are capable of replicating the field conditions after the calibration process. Finding show that LOS differs by maximum one grade between these tools. Segment density obtained from HCM methods is generally higher than the segment density from Vissim microsimulation.

The contents of this report reflect the views of the authors, who are responsible for the facts a... more The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the information presented. This document is disseminated under the sponsorship of the Department of Transportation, University Transportation Centers Program, in the interest of information exchange. The U.S. Government assumes no liability for the contents or use thereof.

Na nasl. str.: A thesis submitted to the faculty of The University of Utah in partial fulfillment... more Na nasl. str.: A thesis submitted to the faculty of The University of Utah in partial fulfillment of the requirements for the degree of Master of Science in Civil Engineering. - Umnozeno za odbranu. - University of Utah, Department of Civil and Environmental Engineering, odbranjeno 12.12.2002. - Bibliografija: listovi 146-148. - Abstract.

This paper investigates the aging of pre-timed traffic control through the use of Synchro and Sim... more This paper investigates the aging of pre-timed traffic control through the use of Synchro and SimTraffic. The first section of the paper presents the concept of aging of signal timing plans and the second part estimates the benefits of optimized timing plans in Synchro in the micro simulation environment of SimTraffic. The theoretical nine-node grid network is used as a test bed to model 21 scenarios of deterministic and 100 scenarios of stochastic traffic demand and distribution changes in link flows. The research does not prove the existence of unique aging measures which could correlate any change in link traffic flows with the benefits of signal retiming. The results show that for networks with unchanged traffic distributions, there is a benefit of up to 3% for up to 5% of uniform growth in traffic demand. When stochastic variations of traffic demand and distribution are introduced, the benefits rise to an average of 35%. The measured benefits from the other field retiming projects confirm that estimations from this study are within the same range.

In 2005, the Utah Department of Transportation (UDOT) installed the Sydney Coordinated Adaptive T... more In 2005, the Utah Department of Transportation (UDOT) installed the Sydney Coordinated Adaptive Traffic System (SCATS) in Park City, Utah, on its network of 14 signalized intersections. A field evaluation compared previous time-of-day actuated-coordinated signal timings with those dynamically computed by SCATS. Travel times, travel time stopped delay and number of stops were collected by driving probe vehicles on the major routes. Intersection stopped delays were also collected to investigate traffic performance on side streets. Overall, SCATS consistently reduced travel times and travel time stopped delay, the average number of stops, and intersection stopped delay for major and minor through movements.

UT-03.28, University of Utah, 2003

This report is a comprehensive investigation of adaptive signal control. The literature review id... more This report is a comprehensive investigation of adaptive signal control. The literature review identifies the various control types and the typical benefits of adaptive control over other signal controls. Congestion, incidents and transit priority all are discussed and examined by modeling, first on a theoretical network, and then on four Salt Lake City area networks using field collected data. This modeling was possible through the University of Utah-built interface between the micro-simulation models CORSIM and VISSIM and the Split, Cycle and Offset Optimization Technique (SCOOT). It is important to note that the SCOOT system is not simulated by attempting to emulate the control algorithms. The micro-simulator sends detector information to the SCOOT system and SCOOT returns signal state, which then is incorporated by the micro-simulator. An actual SCOOT system provides control strategies to the micro-simulation environment. Therefore, if the micro-simulators are believed to be representative of the real-world environment, then the results of the analysis is how SCOOT performance and benefits will exist in the real-world. The test network and corridor were operated at five congestions levels (0.7 v/c to 1.1 v/c) to identify the impact of congestion on benefits. An updated timing plan, optimized in Synchro, was compared to SCOOT controlled operations. The results show that SCOOT improves both network and corridor performance by reducing delay, queue length and travel time. However, SCOOT benefits on networks are higher than the benefits on a corridor. For example, SCOOT improves over optimized Synchro plans at 0.9 v/c, by up to 21 percent for a network. SCOOT improves by up to 13 percent for corridors. Improvements are small for both networks and corridors at and beyond saturation. This supports the field findings that while adaptive control can delay the onset of congestion and reduce recovery time, once saturation flow is reached congestion is inevitable. The performance of SCOOT during incidents of 15, 30, and 45 minute durations for a range of traffic congestion levels shows that SCOOT reduced delay, queue length, and travel time, compared to an

Abstract: Interstate 15 in Utah's Salt Lake City metropolitan region has 38 miles of Hig... more Abstract: Interstate 15 in Utah's Salt Lake City metropolitan region has 38 miles of High-Occupancy Vehicle (HOV) lanes. In September 2006, the HOV lanes became High-Occupancy/Toll (HOT) lanes. For a monthly fee of $50, Single-Occupant Vehicle (SOV) ...

The use of detection to activate protected left-turn phasing has developed primarily through empi... more The use of detection to activate protected left-turn phasing has developed primarily through empirical trial and error and has been instituted without the supporting scientific theory. This study compared the performance of left-turn phasing to provide quantifiable benefits of one phasing over another. Permitted, protected, and protected/permitted (P/P) phasing are analyzed for a range of left-turn volumes and opposing through traffic in order to develop relational curves. The measure of left, through and overall intersection delay is used to compare the different phasing performances. Specific consideration is given to determining the optimal location of the queue detector for P/P phasing. From the analysis, guidelines are developed for determining the type of left-turn phasing based on left-turn volume, opposing through volume and lane geometry. The analysis indicates that P/P phasing provides the best method of left-turn phasing signal control. The P/P phasing allows for a wide r...

American Journal of Traffic and Transportation Engineering, 2019

Many toll facilities have been faced with traffic shortfalls due to inaccurate and over-forecaste... more Many toll facilities have been faced with traffic shortfalls due to inaccurate and over-forecasted toll revenue projections. Therefore calculating optimal toll rates can be a difficult process. Toll rates are often set to reflect the revenue needed to pay back bonds issued to finance the roadway. This research provides an alternative approach to calculating toll rates where revenue can be maximized while still considering the socio-demographics of the region. Several different approaches used in the border region were explored and compared to field data on an existing toll facility in El Paso, Texas. An innovative simulation-based modeling approach was used to test both static and dynamic pricing algorithms. Static tolling results showed optimal toll rates of 0.14/mileand0.14/mile and 0.14/mileand0.08/mile for Border Highway West in the westbound and eastbound directions respectively. The Cesar Chavez Highway has optimal toll rates of 0.12and0.12 and 0.12and0.10/mile in the west and eastbound directions. The dynamic tolling approach showed a max toll rate of 1.56/mileforCesarChavezHighway(westbound)duringthemorningpeakperiodandthenincrementallydecreasedtotheminimumtollrate.However,theeastbounddirectionneverincreasedabovetheminimumtollrateof1.56/mile for Cesar Chavez Highway (westbound) during the morning peak period and then incrementally decreased to the minimum toll rate. However, the eastbound direction never increased above the minimum toll rate of 1.56/mileforCesarChavezHighway(westbound)duringthemorningpeakperiodandthenincrementallydecreasedtotheminimumtollrate.However,theeastbounddirectionneverincreasedabovetheminimumtollrateof0.08 mile. Border Highway West never increased above the minimum toll rate in either direction. The dynamic tolling algorithm prediction is more representative of the optimal tolling rates for the border region-with the exception of Cesar Chavez Highway westbound.

Journal of Engineering and Architecture, 2016

The integration of mesoscopic and microscopic simulation models provide expanded dimensions of mo... more The integration of mesoscopic and microscopic simulation models provide expanded dimensions of modeling capabilities by taking the strengths of both model resolutions. Many transportation agencies, practitioners and researchers are beginning to see the advantages of using multiple levels of resolution when analyzing corridor specific problems. Mesoscopic models use dynamic traffic assignment to reroute traffic given various traffic conditions. Microscopic models are used to analyze traffic conditions at the individual car or lane level. Models are calibrated and validated using data collected in the field. Most practitioners validate their models to existing conditions and then forecast future conditions to predict traffic congestion. Once simulation runs are finished, results are presented to hosting transportation agencies and the project is completed. Very few practitioners collect future field data and compare it to the simulated forecasts. This sort of reverse model validation is referred to as back casting. This paper outlines the complete modeling process from model development, conversion, calibration, consistency, validation and ultimately-model back casting. A case study involving user class restrictions on Interstate 10 in El Paso, Texas was used to analyze how accurate the models were at predicting future conditions. Researcher's simulated truck restricted lanes on the freeway to determine how effective the user class restrictions were on overall traffic speeds and travel times. One year later when the truck lane restrictions were in place, field data was collected to determine how accurate the models were at predicting traffic conditions.