Safe Transportation Research & Education Center

In 2018, SafeTREC conducted a survey on transportation mobility issues among older adults in California. A follow-up survey planned for 2020, just as the COVID-19 pandemic changed life for all residents, was redesigned to assess mobility needs and changes during the Shelter-in-Place order and focused on COVID-19 impacts. Results indicate that the COVID-19 pandemic and subsequent Shelter-in-Place order have had a major impact on senior mobility. Communications for many were restricted to phone, email, texts, social media and video chats. Among those with a medical problem, just over 60% called a doctor or nurse line or went to a doctor’s office, while 11.2% went to an emergency room, and 8.6% did nothing. A total of 8% of respondents said they had run out of food or other important items during the Shelter-in-Place order. Rates of exercise outside the home dropped 20% between January and June 2020, and while over 60% sought outside entertainment in January 2020, by June 2020, nearly 70% accessed their entertainment online at home. Almost 80% of working respondents feared spreading or contracting COVID-19 because of their work or related transportation. Almost 20% felt a lack of companionship or closeness sometimes or often. Over 30% were worried about their current or long-term finances. A total of 84.5% strongly agreed or agreed that the Shelter-in-Place order was necessary. None of the respondents to the follow-up survey were diagnosed with COVID-19, and 88.2% were not concerned about risk of exposure from any member of their household.

Investigating the dynamics behind the likelihood of vehicle crashes has been a focal research point in the transportationsafety field for many years. However, the abundance of data in today's world generates opportunities for deepercomprehension of the various parameters affecting crash frequency. This study incorporates data from many differentsources including geocoded police-reported crash data, curbside infrastructure data and socio-demographic data for thecity of San Francisco, CA. Findings revealed that the GFMNB model provides a better statistical fit than the FMNB andNB model in terms of AIC and log likelihood, while the NB model outperformed both mixture models in terms of BIC dueto model complexity of the latter. Among the signicant variables, TNC pick-ups/dropoffs and duration of parked vehicleswere positively associated with segment-level crashes.

The mobility needs of an aging population is one of the most substantial challenges facing California in the coming decades. The number of residents age 65 and older is expected to double between 2012 and 2050, and the number age 85 and above is expected to increase by over 70% between 2010 and 2030. Declines in physical function related to age may reduce mobility options dramatically. A survey of 510 residents age 55 and older in Contra Costa County was conducted to determine mobility patterns and limitations related to age and other factors. Results of the survey indicate that a majority of seniors are car dependent. However, some older adults miss important activities due to mobility limitations associated with increasing age, poorer health, living alone, not having a licensed driver in the household, and having a disability. Mobility options are also limited in some geographic areas and demographic groups. Importantly, older adults want to “age in place.” Based on these findings and those in related studies, the travel options and the quality of life for older adults, now and in the future, can be greatly enhanced if efforts are made to develop mobility solutions beyond use of private vehicles. The findings support the recommendations of recent regional plans such as the Coordinated Public Transit–Human Services Transportation Plan (2018), adopted by the Metropolitan Transportation Commission (MTC) of the San Francisco Bay Area, which recommends supporting a range of mobility options centered around shared mobility and accessibility for populations at risk for limited mobility.

Traffic safety decisions are based predominantly on information from police collision reports. However, a number of studies suggest that such reports tend to underrepresent bicycle and pedestrian collisions. Underreporting could lead to inaccurate evaluation of crash rates and may under- or overestimate the effects of road safety countermeasures. This review examined ten studies that used data linkage to explore potential underreporting of pedestrian and/or bicyclist injury in police collision reports. Due to variations in definitions of reporting level, periods of study, and study locations, it was difficult to directly compare the studies. Even among the six studies using the hospital link definition, estimates of reporting levels ranged from 44 to 75 percent for pedestrian crashes, and from 7 to 46 percent for bicycle crashes, suggesting a severe underreporting problem. However, few of the studies provided estimates of the error around their reporting level estimates, and as a result, it is difficult to determine the true level of underreporting. It may be that bicycle and pedestrian crashes appear in both police and hospital datasets but are less likely to be linked. Due to linkage error, link rate can only be used to estimate reporting level. Without the variance of that estimate, the effect of underreporting on traffic safety analyses cannot be accurately determined. Future studies should include estimates of the error present in their data linkage process for greater accuracy of the underreporting in police data. Datasets should be designed for easier linkage with hospital data and other datasets.

A significant proportion of fatalities from motor vehicle collisions (MVC) could be prevented through better emergency medical service (EMS) care. Despite a lack of conclusive research, there is a consensus that prehospital time (the time between the MVC and the patient’s arrival at the hospital) must be reduced as much as possible. Many studies use response time (the time between EMS dispatch and arrival at the scene) as an indicator of overall prehospital time and a metric of EMS performance. However, there are other components of prehospital time that may be equally important, including the discovery time between the collision and EMS notification, the on-scene time, and the transport time from the scene to the hospital. In rural MVCs, the discovery time can be substantial if there are no witnesses or survivors capable of calling emergency services. Technologies that automatically detect MVCs can shorten discovery times in such circumstances. Transport times depend on the distance between the crash scene and the hospital; this time could be reduced by increasing access to trauma centers, especially in rural areas. On scene time is a component of the total time, however there is a trade-off between minimizing scene time to reduce total time and providing optimal on-scene care. Increasing capacity of EMS personnel and/or utilizing technology such as telemedicine should be considered as part of this trade-off. Future research is needed to determine the relative benefits and costs of reducing any of these segments of prehospital time.

Fatal or injury collisions in California must be reported to the California Highway Patrol (CHP) for inclusion in the Statewide Integrated Traffic Records System (SWITRS). After records have been entered into SWITRS they are made publicly available and are accessible through the CHP’s report and data retrieval site called I-SWITRS. However, records accessed in SWITRS are considered provisional and can be updated several years after initial entry. This includes the injury severity level of collisions. If the collision data was accessed prior to an injury severity update, the agency retrieving the data may unknowingly be working with an outdated version. This can have an impact on government agencies use of data driven safety analyses to apply for safety improvement funding in order to achieve key safety goals in reducing fatal and serious injury collisions. This paper evaluated the frequency and level of injury severity changes for severe injury and fatal collisions that occurred in 2016 and which were retrieved at four different times between March 2017 and June 2018. In total, 94 injury collisions were upgraded to fatal collisions (2.653%) and 2 fatal collisions were downgraded to severe injury collisions (0.056%) out of the 3,543 total fatal collisions that occurred in 2016. The authors concluded that government agencies need to perform regular checks of their data to ensure that fatal and severe injury collisions are properly accounted for to maximize their ability to achieve safety performance targets.

Fatal or injury collisions in California must be reported to the California Highway Patrol (CHP) for inclusion in the Statewide Integrated Traffic Records System (SWITRS). After records have been entered into SWITRS they are made publicly available and are accessible through the CHP’s report and data retrieval site called I-SWITRS. However, records accessed in SWITRS are considered provisional and can be updated several years after initial entry. This includes the injury severity level of collisions. If the collision data was accessed prior to an injury severity update, the agency retrieving the data may unknowingly be working with an outdated version. This can have an impact on government agencies use of data driven safety analyses to apply for safety improvement funding in order to achieve key safety goals in reducing fatal and serious injury collisions. This paper evaluated the frequency and level of injury severity changes for severe injury and fatal collisions that occurred in 2016 and which were retrieved at four different times between March 2017 and June 2018. In total, 94 injury collisions were upgraded to fatal collisions (2.653%) and 2 fatal collisions were downgraded to severe injury collisions (0.056%) out of the 3,543 total fatal collisions that occurred in 2016. The authors concluded that government agencies need to perform regular checks of their data to ensure that fatal and severe injury collisions are properly accounted for to maximize their ability to achieve safety performance targets.

SafeTREC, transportation systems

This report summarizes the information gained from two community forums held in Latino communties in California, provides an analysis of trends in injury and demographic data, and reviews best practices for increasing safety and preventing injury in Latino populations. It highlights pressing traffic safety needs and presents recommendations. It is our goal that this report will serve as a prototype for policy, enforcement and program development to address traffic safety issues for Latinos in California.