http://www.rssboard.org/rss-specification 720 https://escholarship.org/uc/its_tsc_wp/rss Recent eScholarship items from Working Papers Fri, 4 Sep 2026 17:36:03 +0000 https://escholarship.org/uc/item/6rg2r0cj The Vehicle Weight Safety Study provides supporting analysis for the California Transportation Commission’s study on therelationship between vehicle weight and road user injury and roadway degradation required by Assembly Bill (AB) 251, which was signed by the Governor in October 2023. To inform the work of the CTC, this report summarizes trends of road user injuries and fatalities in California and potential factors contributing to these trends (Chapter 2); summarizes trends in vehicle weight, size, and height for registered vehicles in California (Chapter 3); documents the landscape of policy solutions focused on vehicle size that might address California’s road user injuries and fatality challenge (Chapter 4); analyzes the impact of potential weight-based fees on consumer vehicle purchasing behavior (Chapter 5); and, analyzes the relationship between shifts in passenger vehicle weight and degradation of road infrastructure (Chapter 6). https://escholarship.org/uc/item/6rg2r0cj Mon, 2 Mar 2026 00:00:00 +0000 Raifman, Matthew, PhD Griswold, Julia, PhD Brownstone, David, PhD Harvey, John, PhD Stahl, Amalia, MA Atkins, Jon Johnson, Celia Anderson, Michael, PhD Vaco, Federico, PhD https://escholarship.org/uc/item/12b31107 This study provides a preliminary investigation into the relationship between urbanization and traffic collisions by analyzing the spatial patterns in Sacramento County, California from 1998 to 2008 using&nbsp;urban land classifications and traffic collision data. The ArcGIS directional distribution tool was used to&nbsp;create standard deviational ellipses to investigate the distributional trend of urban land and traffic&nbsp;collisions over time. Statistical outputs representing changes of geographical centroids, elliptical areas,&nbsp;and standard distances (long and short axes) were then compared. Collisions were also subset by severity&nbsp;level to account for inherent differences in the spatial distribution of different types of collisions. The&nbsp;results provided insight into the macroscopic spatial patterns of urban land and traffic safety and their&nbsp;relationships. The limitations of the method and the need for further research were discussed. The&nbsp;approach... https://escholarship.org/uc/item/12b31107 Tue, 2 Dec 2025 00:00:00 +0000 Kang, Sanghyeok Spiller, Margot Jang, Kitae Bigham, John M Seo, Jongwon https://escholarship.org/uc/item/75q8n761 Hit-and-run collisions—those in which a driver involved in the collision leaves the scene before the arrival of law enforcement officials—are a unique type of traffic violation because the driver's decision is a question of damage control rather than damage prevention. To reduce hitand-run violations, individual state laws impose legal sanctions to deter drivers from leaving the collision scene prematurely. Deterrence Theory dictates that compliance with laws is associated with the certainty, severity, and swiftness of punishment. The purpose of this study is to explore the deterrent effect of legal sanctions on the rate of hit-and-run collisions. Legal sanctions for hitand-run violations across the United States were compared with the prevalence of pedestrian hitand-run collisions in those states. Specifically, the severity of punishment, the certainty of punishment, and the excess legal sanctions of hit-and-run were compared with the rates of hitand-run. The results of these... https://escholarship.org/uc/item/75q8n761 Tue, 2 Sep 2025 00:00:00 +0000 Grembek, Offer, PhD Griswold, Julia, PhD https://escholarship.org/uc/item/01j3411t This study examines data from the California EMS Information System (CEMSIS) to identify factors that influence prehospital time for EMS events related to motor vehicle collisions (MVCs). While only 19 percent of the United States population resides in rural areas, over half of all traffic fatalities involve rural motor vehicle collisions. Rural and urban MVCs result in similar injury severities, however relative inaccessibility of trauma centers and prehospital EMS time (activation, response, and transport time) likely contribute to the generally higher mortality rate in rural areas. For the present study, 24 CEMSIS data variables were requested, many of which involved missing data, which severely restricted the potential analysis of the impact of EMS response times. However, the findings did show that average overall EMS time (including response, scene and transport time) were approximately twice as long for collisions in rural zip codes compared with urban zip codes. Several... https://escholarship.org/uc/item/01j3411t Tue, 14 May 2019 00:00:00 +0000 Doggett, Sarah Ragland, David R. Felschundneff, Grace https://escholarship.org/uc/item/9xg8n6vr <p>The multimodal transportation network includes a mix of inherently different modes. In addition to differences in price, range, and comfort of travel, these modes differ in mass and velocity, which correspond to different orders of magnitude in the kinetic energy carried. This discrepancy in kinetic energy affects both the level of protection of each mode, and the level of damage it can inflict on users of other modes. Unfortunately, accounting for both sides of a crash is often overlooked. While the quantities and variables of collected data continue to increase, the analyses conducted and the tools developed remain focused on the victims of crashes. The existing approach limits the ability to explore the underlying mechanism of traffic crashes since there are two sides to every crash. This manuscript proposes a framework for studying traffic safety which takes into account the interaction between all modes in a network. At the core of the framework is a square matrix, I.... https://escholarship.org/uc/item/9xg8n6vr Sun, 12 Jul 2015 00:00:00 +0000 Grembek, Offer https://escholarship.org/uc/item/9vn6j0x3 The only way to absolutely prevent all drivers from going around lowered gates at level rail-highway crossings is to make it physically impossible, or at least very difficult, for them to do so. While there are various options to accomplish this (constructing a separation of grade, closing the crossing, or deploying an impenetrable concrete barrier), most have high monetary or social costs. Alternative approaches—such as channelization devices and long-arm gates—while not 100 percent effective, can be used to prevent deaths and injuries while remaining economically feasible. Research has shown that the addition of channelization devices can dramatically reduce the number of violations at level rail-highway crossings. While long-arm gates appear to be effective, additional study is needed to determine their suitability for individual locations. Unfortunately, even when overall rail crash totals for the country or for a given state are high, crashes at specific crossings are relatively... https://escholarship.org/uc/item/9vn6j0x3 Sun, 12 Jul 2015 00:00:00 +0000 Cooper, Douglas L Ragland, David R Felschundneff, Grace https://escholarship.org/uc/item/9qg3s59b Road deaths are forecast to double by 2020, with the burden falling most heavily on low- and middle-income countries and, within those countries, on the most vulnerable and poorest road users. Half of the 1.2 million people killed and 50 million injured in road crashes each year are pedestrians, motorcyclists, bicyclists, and users of unsafe public transport; and more than 90 percent are from low- and middle-income countries. Because these are the areas where rapid motorization is taking place, the issue of safety in increasingly multi-modal environments is now of critical importance, particularly for pedestrians and bicyclists, since as vulnerable road users (VRU), they comprise a large proportion of injuries and deaths, and similar strategies for prevention of injuries and fatalities for these two groups are available. Although a great deal of additional research is needed to determine the costs and benefits of various proposed solutions, some basic principles can be identified... https://escholarship.org/uc/item/9qg3s59b Sun, 12 Jul 2015 00:00:00 +0000 Ragland, David R Grembek, Offer Orrick, Phyllis Felschundneff, Grace https://escholarship.org/uc/item/8cs2g40c The San Francisco pedestrian volume modeling process refined the methodology used to develop previous intersection-based models and incorporated variables that were tailored to estimate walking activity in the local urban context. The methodology included two main steps. First, manual and automated pedestrian counts were taken at a sample of 50 study intersections with a variety of characteristics. A series of factor adjustments were applied to produce an annual pedestrian crossing estimate at each intersection. Second, log-linear regression modeling was used to identify statistically-significant relationships between the annual pedestrian volume estimate and land use, transportation system, local environment, and socioeconomic characteristics near each intersection. Twelve alternative models were considered, and the preferred model had a good overall fit (adjusted-R 2= 0.804). As identified in other communities, pedestrian volumes were positively associated with the number of... https://escholarship.org/uc/item/8cs2g40c Sun, 12 Jul 2015 00:00:00 +0000 Schneider, Robert J. Henry, Todd Mitman, Meghan F. Stonehill, Laura Koehler, Jesse https://escholarship.org/uc/item/85f9b3s8 The purpose of this study is to provide an exploratory analysis of the proportion of pedestrians, bicyclists, and drivers exhibiting four specific behaviors at 12 intersections near transit stations in 4 the San Francisco Bay Area. The target behaviors include: 1) pedestrians crossing the roadway while using a mobile device, such as a cell phone, 2) pedestrians crossing a signalized intersection against a red light, 3) bicyclists running a red light at a signalized intersection, and 4) automobiles turning right on red without stopping. These four behaviors are important because they may lead 8 to pedestrian crashes. Field observations show a range of observed pedestrian and bicycle violation of red lights. At some locations as few as 2.4% of non-motorized road users violated red lights, whereas 40% did at other sites. The range of vehicles violating red lights was somewhat higher, with 20% to 62% of drivers turning right illegally on a red light. Male pedestrians were more likely... https://escholarship.org/uc/item/85f9b3s8 Sun, 12 Jul 2015 00:00:00 +0000 Cooper, Jill F. Schneider, Robert J. Ryan, Sherry Co, Sean https://escholarship.org/uc/item/1tm284cm Non-emergency medical transportation (NEMT) can prevent emergency care as a result of delayed or missed medical appointments. Medicaid provides NEMT for low income individuals who have no other means of transportation and this is a critical component of the health care delivery system. This study examined cancelled trips in Medicaid adults age 65+ to explore whether barriers persist for a growing segment of the population who face particular challenges of age-related declines in health and function. Multivariate logistic regression analyses were conducted using transportation brokerage data for Delaware members who intended to travel during 2008-2010, modeling the odds of all cancellations and then these mutually exclusive types: (1) client cancelled; (2) client obtained alternative transportation; and (3) client cancelled due to health. Over half of the cancelled trips were attributed to client reasons. Black race was associated with client canceling (OR=1.4) and canceling due... https://escholarship.org/uc/item/1tm284cm Sat, 11 Jul 2015 00:00:00 +0000 MacLeod, Kara E. Ragland, David R. Prohaska, Thomas R. Irmiter, Cheryl Irmiter Satariano, William Leary, Mary A. https://escholarship.org/uc/item/1pb9v7xq Growing interest in sustainable transportation systems and livable communities has created a need for more complete measures of pedestrian travel. Yet, many performance measures do not account for short pedestrian movements, such as walking between stores in a shopping district, walking from a street parking space to a building entrance, or walking from a bus stop to home. This study uses a 2009 intercept survey and the 2009 National Household Travel Survey to quantify pedestrian travel to, from, and within 20 San Francisco Bay Area shopping districts. Overall, walking was the primary travel mode for 21% of intercept survey and 10% of NHTS tours with stops in these shopping districts. However, detailed analysis of pedestrian movements showed that walking was common on respondent tours (52% of intercept survey tours included some walking) and that walking was used on the majority of trips within these shopping districts (65% of intercept survey trips and 71% of NHTS trips within... https://escholarship.org/uc/item/1pb9v7xq Sat, 11 Jul 2015 00:00:00 +0000 Schneider, Robert J. Pande, Swati S. https://escholarship.org/uc/item/1zn7w26v <p>This paper presents findings from a recent study on roadway design preferences among pedestrians, drivers, bicyclists, and public transit users along a major urban corridor in the East San Francisco Bay Area.  Sponsored by the California DOT, the research focused on exploring design preferences that could increase perceived traffic safety, walkability, bikability, and economic vitality along urban arterials.  </p><p>Results from an intercept survey showed that all user groups desire similar roadway design features along the test corridor, which carries 25,000-30,000 motorists bi-directionally and has comprehensive sidewalk coverage, but no bicycle facilities.  In an open-ended question about street improvements to enhance perceived traffic safety, all respondent groups requested the same top five improvements.  Bicycle lanes were ranked first by pedestrians, drivers, and bicyclists (fifth by public transit respondents), and improved pedestrian crossings were ranked second by... https://escholarship.org/uc/item/1zn7w26v Tue, 25 Jun 2013 00:00:00 +0000 Sanders, Rebecca L Cooper, Jill F