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| Institutional Approaches for Interjurisdictional Traffic Systems Management (2003-2004) | [ back to top ] |
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Investigator: Michael G. McNally (UCI) and SPMattingly (UT Arlington) Support: Caltrans and USDOT via PATH Summary: The last decade of experience with implementing, or in some cases not implementing, Intelligent Transportation Systems (ITS) technologies has led to the identification of a broad range of institutional coordination problems. A critical review of these implementation projects and the identification of the associated institutional cooperation problems should provide a body of knowledge that, when interpreted in context of the projects and institutions at play, will lead toward the development of a "best practices" prescriptive policy guide. The goal of the proposed research is to develop such a policy guide, including sample institutional agreements, to identify potential institutional constraints prior to a project startup [ Project Web Site ] | |
| Handheld Travel Survey Technology to Supplement Vehicle Tracking (2003-2004) | [ back to top ] |
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Investigator: Michael G. McNally Support: Caltrans and USDOT via UCTC Summary: An experimental shared-use station car program using electric vehicles was implemented in association with several public and private sector organizations in Irvine, CA. The goal of this program was to demonstrate the potential of linking shared-use electric vehicles with conventional line-haul public transit services to provide automobile-like accessibility at the ends of the commute trip. The decision to travel with the shared-use vehicles was studied through the examination of the process of how participants scheduled activities before and after shared-use vehicles become a travel option. The goal of the research project was to develop and assess the effectiveness of GPS-based in-vehicle tracking technologies and web-based travel surveys supplemented with a GPS-based handheld device to track travel/activity when using non-program vehicles. The handheld device continuously records and stores spatial position and dumps this data via a wireless link to the in-vehicle device when activity and travel away fro mthe program vehicle are completed. [ Project Web Site ] | |
| Applications of Microsimulation Models to Transportation Planning (2002-2004) | [ back to top ] |
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Investigator: Michael G. McNally and W.W.Recker Support: California Department of Transportation Summary: The conventional travel forecasting (4 step) model is a rather different tool than traffic microsimulation, with different objectives, theory, data needs, and applications. A significant impetus to the development of microsimulation modeling capabilities, particularly in a planning rather than operational context, is to take conventional forecasting to the "next level" to more carefully assess future impacts spatially and temporally. The integration of these two modeling approaches is thus neither intuitive nor simple. Microscopic simulation models are capable of evaluating transportation facility plans and design alternatives as well as traffic operation strategies. A lack of appropriate guidance and/or direction may lead to inappropriate use of and inaccurate results from these models. As Caltrans' districts use microsimulation models with increasing frequency, a standardized guidance and evaluation process would facilitate model application and analysis, as well as the comparative interpretation of model results. UCI's Center for Traffic Simulation Studies (CTSS) provided assistance to Caltrans in three broad categories: (1) On-Call Direct Support, (2) Technical Guidance, and (3) Research Related Support. [ Project Web Site ] | |
| Assessing the Influence of Residential Location Changes on Travel Behavior (2001-2003) | [ back to top ] |
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Investigator: Michael G. McNally Support: U.S. Department of Transportation and California Department of Transportation via UCTC Summary: There are certain fundamental transportation problems that have remained problems, in part, due to an inability to effectively collect the data necessary to address the problem. One such problem involves the "learning" process by which a household re-locating into a new neighborhood evolves new household activity patterns. More specifically, when a household relocates, what are the immediate and longer term impacts on travel behavior of the local activity and transportation systems? How do household travel patterns evolve? What are the new choices and how does knowledge of these choices evolve. This project proposes to integrate technologies developed in prior UCTC, PATH, and Testbed research projects to facilitate the observation of a small number of households re-locating from other areas in Orange County, CA to selected new home developments in Irvine. We will install in-vehicle GPS/Wireless Communication units in all household vehicles to measure specific vehicle use for a multi-day period prior to moving, upon re-locating, and a few months after relocating to selected Orange County neighborhoods. The sampled households will also use REACT!, an computer-based survey research software developed in prior UCTC research, to record their household activities during the same period. The TRACER GPS system data will be integrated with the REACT! software to provide vehicle tracings and timings to respondents. [ Project Web Site ] | |
| OCTA Traffic Microsimulation Model (2001-2003) | [ back to top ] |
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Investigator: Michael G. McNally Support: Orange County Transportation Authority (OCTA) Summary: The Orange County Transportation Authority (OCTA), responsible for transportation planning and modeling in Orange County, has recently updated the Orange County Transportation Analysis Model (OCTAM3) for Base Year 1998. OCTAM 3.0 incorporates state-of-the-practice modeling components that are consistent with the new Southern California Regional Transportation Model and provides a regional travel forecasting base for transportation planning work in the County. The OCTAM model is regional in nature and suited for macro-level analysis. The objective of this project is to assist OCTA in evaluating and integrating a traffic micro-simulation model with the "macro-simulation" OCTAM model to allow a more detailed evaluation of projects through the analysis of various measures of effectiveness. OCTA has identified candidate application projects (including network infrastructure improvements and operational enhancements). [ Project Web Site ] | |
| Modeling the Dynamics of Activity Scheduling (1997-98) | [ back to top ] |
| Investigator: Michael G. McNally Support: U.S. Department of Transportation and California Department of Transportation via UCTC Summary: Computational process models (CPM), which have the ability to replicate interdependent choices made by an individual, can improve our understanding of the activity scheduling process. They can also be used with discrete choice models and microsimulation techniques to forecast the consequences of policy measures. This research builds a geographical information system-interfaced CPM which can be used to examine the process of human activity scheduling. Using a GIS land-use and network data base, the model allows location of activities to exact locations on the street network. Data for the model are drawn from 1985 and 1994 travel and activity surveys from Portland, Oregon, and from other sources. The research also devises practical ways of applying the model to advanced traveler information systems (ATIS). | |
| An Activity-based Assessment of Trip Generation and the Temporal Stability of Travel Patterns (1996-97) | [ back to top ] |
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Investigator: Michael G. McNally Support:Funded by the US Department of Transportation and Caltrans via UCTC Summary: A systematic assessment of two explicitly related dimensions of travel behavior was driven by the increased interest in the development and implementation of activity-based modeling approaches brought about in the ISTEA/NEXTEA era given federal mandates to improve current modeling practice. An activity-based approach to trip generation modeling was developed which integrated household activities, land use distributions, regional demographics, and transportation networks in a framework which explicitly recognizes the complexity of travel behavior in terms of spatial and temporal constraints, household interactions, transport accessibility, and its inherent activity-derived basis. Intended to provide a more policy sensitive alternative to conventional transportation models, this approach utilizes activity-based concepts in (1) defining a new model and (2) in assessing the temporal stability of the basic unit of analysis, the individual and household travel-activity pattern. The research utilized two extensive, multi-year databases: the 1976 and 1991 Orange County database (comprising conventional trip diaries and GIS-based land use and transportation data) and the 1985 and 1994 Portland, Oregon database (comprising 2-day activity diaries and an extensive supporting GIS-based activity data). Results included (a) an assessment of the temporal stability of individual and household travel-activity patterns, (b) the generation and classification of daily activity patterns, and (c) the development and evaluation of an activity-based generation model which reflects the influence of accessibility and maintains spatial and temporal linkages in travel behavior. | |
| Activity-Based Evaluation of Travel Characteristics in Alternate Land Development and Network Structures (1995-96) | [ back to top ] |
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Investigator: Michael G. McNally Support: U.S. Department of Transportation and California Department of Transportation Summary: This research applied an activity-based approach to investigate fundamental characteristics of travel behavior. The approach integrated household activities, land use distributions, regional demographics, and transportation networks in a framework which explicitly recognized the complexity of travel behavior in terms of spatial and temporal constraints, household interactions and transport accessibility. The research was designed to provide the basic inputs to more policy-sensitive alternatives to the conventional modeling process by incorporating activity-based concepts with fundamental relationships which exist between the activity and transport systems. The research utilized two extensive, multi-year databases: the 1976 and 1991 Orange County database (comprising conventional trip diaries and GIS-based land use and transportation data) and the 1985 and 1994 Portland, Oregon database (comprising 2-day activity diaries and an extensive supporting GIS-based activity data). Research results included (a) an extension of preliminary work with Orange County data, and a comprehensive investigation of the Portland database, (b) the generation and classification of activity patterns for both data sets, and (c) a comparative assessment of the relative contributions of external factors (primarily land use and network structure) on travel behavior in each data base. | |
| Evaluation of the Anaheim Advanced Traffic Control System FOT (1995-98) | [ back to top ] |
| Investigator: Michael G. McNally,
R.Jayakrishnan, James E. Moore II (USC), and C. Arthur MacCarley (CPSLO) Support:Federal Highway Administration and California PATH Summary: A systematic evaluation of the performance and effectiveness of a Field Operational Test (FOT) of a Advanced Traffic Control System was conducted from 1995-97 in the City of Anaheim, California. The FOT was executed by a consortium consisting of the California Department of Transportation, the City of Anaheim, and the Odetics Corporation. The FOT was cost-share funded by the Federal Highway Administration (FHWA) as part of the Intelligent Vehicle Highway System (IVHS) Field Operational Test Program. The subject FOT involved an integrated Advanced Transportation Management System (ATMS) which extended the capabilities of then existing freeway and arterial traffic management systems in the City of Anaheim. The FOT area coincides with major employment and residential concentrations and includes such major event locations as Disneyland, the Anaheim Convention Center, Anaheim Stadium, and the Anaheim Arena. The area corresponds to the Anaheim portion of the UCI/Caltrans ATMS Testbed. The subject FOT is distinguished by two key technical features: arterial traffic control supervised by the SCOOT (Split Cycle and Offset Optimization Technique) algorithm, and a VTDS (Video Traffic Detection System) developed by Odetics for automated detection of metrics required for optimal traffic management on arterials. Results showed that SCOOT, which was implemented in a non-standard fashion utilizing existing detectorization, performed in a similar manner as the UTCS system (SCOOT was installed in parallel to existing UTCS) despite the non-standard detectorization and a range of technical and institutional limitations. The prototype VTDS did not meet are planned system performance objectives, but both the VTDS and SCOOT functioned at a level sufficiently promising that SCOOT and a second-genration VTDS are currently utilized in the City. A third FOT component technology, 1.5 Generation Control, was not successfully completed.
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| Evaluation of the Irvine Integrated Freeway/Arterial Traffic Control System Field Operational Test (1995-99) | [ back to top ] |
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Investigator: Michael G. McNally,
R.Jayakrishnan, James E. Moore II (USC), and C. Arthur MacCarley (CPSLO) Support:Federal Highway Administration and California PATH Summary: A systematic evaluation of the performance and effectiveness of a Field Operational Test (FOT) of a Advanced Traffic Control System was conducted from 1995-97 in the City of Irvine, California. The FOT was executed by a consortium consisting of the California Department of Transportation, the City of Irvine, National Engineering Technologies Inc (NET), and Farradyne Systems Inc (FSI). The FOT was cost-share funded by the U.S. Federal Highway Administration (FHWA) as part of the Intelligent Vehicle Highway System (IVHS) Field Operational Test Program. The FOT involved an integrated Advanced Transportation Management System (ATMS) which extended the capabilities of existing freeway and arterial traffic management systems in the Irvine area of Orange County. The area corresponds to the Irvine portion of the UCI/Caltrans Advanced ATMS Testbed. Its key features were the integration and real-time control of current and evolving traffic operations technologies to achieve a degree of integrated control of the freeway and neighboring arterial networks in the defined area. Specific FOT technologies for the City of Irvine included OPAC, an adaptive traffic signal control system running under MIST, a traffic management information system, and installed on state-of-the-art 2070 traffic controllers. Caltrans District 12 technologies included SWARM, an adaptive ramp metering system. All technologies were to be integrated for cooperative traffic management. After baseline performance assessment of the existing control systems, a series of before-after field studies corresponding to the FOT deployment schedule was to be completed. Overall FOT evaluaiton also considered administrative, personnel, financial, legal, liability, socio-technical, and transferability issues related to all aspects of the FOT. The FOT technologies were developed and delivered but never successfully passing system acceptance testing (in the case of Irvine technologies) or successfully deployed (in the case of Caltrans D12). A wide range of institutional and technical limitations and constraints were identified as contrinuting o the failure of the FOT.
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| Assessing Impacts of the Northridge Earthquake on Travel Behavior, Traffic Operations, and Network Performance (1994-95) | [ back to top ] |
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Investigator: Michael G. McNally and R. Jayakrishnan Support: Funded by the Federal Highway Administration and the Bureau of Transportation Statistics Summary: Although freeway infrastructural damage resulting from the January 1994 Northridge earthquake was primarily confined to areas near the epicenter in the San Fernando Valley and also in west Los Angeles, the impact on the flow of traffic was more widespread. The destruction of critical links in the highway transportation network reduced connectivity and available routes and also removed capacity from the system. From the perspective of system operation and performance, two key issues were addressed. First, what fundamental changes in network performance occurred as a direct consequence of the earthquake, and second, at what rate did traffic return in the post-quake recovery period? These issues were addressed through the examination of observed traffic volumes from loop detectors on the southern California freeway network. These results were supplemented by the application of a standard transportation network model to estimate traffic conditions in locations which are not detectorized. A examination of serial traffic data at selected locations provided an indication of the practical capacity of the network at these sites and their role in handling shifts in travel demand resulting from quake damage. The effectiveness of the freeway network to provide alternate routes for trip diversion was assessed via analysis of sites along defined corridors in comparison to shifts in other regional corridors. Measuring temporal changes in traffic volumes provided insight into the resiliency of a network experiencing a major reduction in capacity and connectivity as well as disruptions in daily travel patterns. A baseline date prior to the earthquake was selected for comparison of post-quake performance. Data was collected for the baseline date, for a date one week after the quake, and for four separate dates following the re-opening of damaged freeway segments. Detector locations were selected for freeway segments which could be characterized as either impacted or non-impacted, where impacted implies either directly impacted via capacity or connectivity reductions or indirectly impacted via re-routed traffic from other segments. Locations were constrained by the placement and functionality of detectors providing volume data over the analysis period. Loop data was summarized for 15 minute counting intervals for each of the selected 24 hour periods. Although data was collected for most sites until June 1994, most locations exhibited volumes at pre-quake levels by mid-March, suggesting a two month recovery period (corresponding travel time impacts are unclear). Traffic volumes near the three northern system breaks (I-5, SR-14, and SR-118) approximated normal levels by mid-March, well in advance of complete freeway reconstruction (between mid-May and July). In the immediate post-quake period, interesting volume shifts were evident. Northbound volumes in this area increased during the mid-day period and dropped off sharply in the PM-peak, southbound volumes were consistently yet minimally lower in the AM-peak, and night volumes showed small to moderate relative increases. US-101 served as an alternate route for a modest percentage of diverted travelers, especially in the southbound direction from February to April. Near the southern system (I-10) break, traffic volumes increased along parallel surface streets and to some degree on the parallel I-105 freeway to the south. Rapid reconstruction returned the freeway to normal performance levels in March. Not surprisingly, little or no impact was observed on the freeway system beyond these identified impact areas of the freeway network. The system's resiliency is attributed to the extreme redundancy in network connectivity and capacity, and to the limited spatial extent of the damage. | |
| Advanced Public Transit Systems Planning: Phase I - Transit Assignment and Implications of Route Choice under Information (1993-94) Advanced Public Transit Systems Planning: Phase II - Operational Model for Transit Network Evaluation (1995-96) |
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Investigator: R. Jayakrishnan and
Michael G. McNally Support:Funded by the Caltrans Transit Research Program and the University of California Transportation Center Summary: This research resulted in the improvement of an existing multipath transit assignment model. Multipath transit assignment models have been implemented in transportation planning software packages such as EMME/2. The use of approximate expressions for the expected waiting time at a node and the resulting ridership probabilities, however, raise doubts about the reliability of the results. The research objective was to improve the transit assignment model developed by Spiess and Florian (1989). That approach presents the transit assignment problem with a fixed set of transit lines, where a traveler chooses the strategy that allows the desired destination to be reached at a minimum expected cost. Route choice is based on the concept of optimal strategies. The Spiess and Florian expressions for waiting time at a node and for line probabilities do not replicate the behavior of uniform random passenger arrivals at a node for a set of fixed transit lines with constant headways. The exact expressions for waiting time and line probabilities were derived based on a theoretical framework involving basic probability functions and properties of constant interarrival distributions. A recursive solution was presented. | |
| An Assessment of the Impacts of Traditional Neighborhood Development: on Suburban Accessibility and Urban Form (1991-94) | [ back to top ] |
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Investigator: Michael G. McNally Support: U.S. Department of Transportation and California Department of Transportation Summary: This three year research project focused on a formal assessment of the potential of Traditional Neighborhood Development (TND) design concepts to ameliorate the impacts of excessive growth on transportation infrastructure. Through basic changes in land use and street geometric and network design, TND attempts to improve accessibility via increased efficiency in travel/activity patterns. Improvements in network connectivity are coupled with lower speeds resulting in comparable travel times but reduced vehicle miles traveled, less congestion, and improved air quality. | |
| Real-Time Provision of Traveler Information (1989-93) | [ back to top ] |
| Investigator: Michael G. McNally,
W. W. Recker, and Jeffrey L. Adler Support: Funded by California PATH and the Caltrans ATMS Testbed Summary: Interactive simulation of the dynamics of driver behavior in response to Advanced Traveler Information Systems (ATIS) provides a response envelope for the design, implementation, and operation of ATMS/ATIS. The simulator, FASTCARS, models pre-trip and enroute driver decision-making via a multimedia, microcomputer-based, interactive environment which presents real-time information from such driver-selected intelligent vehicle-highway system technologies as Highway Advisory Radio and an In-Vehicle Navigation System, in addition to variable message signs and conventional driver information sources (including information signs, network familiarity, and direct observation of traffic conditions). The focus is on the process of search and utilization of information rather than on human factors issues. Initial analyses have suggested an increase in travel utility for less familiar drivers and a limited use of new technologies for drivers with greater network familiarity. | |
| A Model of Complex Travel Behavior (ongoing) | [ back to top ] |
| Investigator: Michael G. McNally Support: Funded by National Science Foundation Summary: This project represents ongoing research endeavors focused on the examination of complex travel behavior. Prior research had lead to the development, evaluation, and application of STARCHILD, a research-oriented, activity-based model of complex travel behavior. Extended research was directed toward the examination from a cognitive behavioral point of view of the processes of destination choice and path selection. This activity was undertaken jointly with researchers at UC Santa Barbara as part of the process of building a GIS-based model of complex travel behavior, based on STARCHILD, and designed to identify feasible opportunity sets for destination choice and allocation models. | |
