IntroductionRoad injuries by a data-driven process. Caltrans

IntroductionRoad safety has been a noteworthy transportation topic in the U.S. as it serves as a regional mobility choice which can also affect people’s lives. Traffic fatalities per 100 vehicle miles traveled (VMT) increased by 10 percent in California from 2012 to 2015 whereas the overall U.S. traffic fatalities increase per 100 VMT was 1 percent (Figure 1) (NTHSA). According to an NHTSA report, road crashes account for approximately $871 billion economic loss and societal harm in the United States. Economic savings can be achieved if we can prevent the fatalities and serious injuries as most of the crashes are preventable occurrences (Chen, L., Chen, C., Ewing, R., Mcknight, C. E., Srinivasan, R., & Roe, M. 2013). The purpose of this paper is to examine the characteristics of traffic fatalities by transportation mode in Los Angeles County to evaluate Road Safety counter-measures. State Department of Transportation U.S. Department of Transportation requires state DOT’s to develop and update the Strategic Highway Safety Plan (SHSP) which is a major component to reduce the fatalities and serious injuries in a state. The California Department of Transportation (Caltrans) coordinates with various agencies which work towards reducing the fatalities and serious injuries by a data-driven process. Caltrans is also required to develop and update the SHSP plan. The SHSP plan would be developed for all roadway networks within the state and is also developed to accommodate all modes of transportation. Through SHSP the state aims to move Towards Zero Deaths (TZD) or vision zero wherein the state would intend to reduce fatal crashes by 3 percent annually and serious injuries by 1.5 percent annually (“Strategic Highway Safety Plan (SHSP) – Safety | Federal Highway Administration,” n.d.). Vision ZeroSeveral states and cities have adopted Vision Zero or Towards Zero Death (TZD) initiatives to prevent the fatalities and serious injuries.  Vision Zero was initiated by Sweden whose fundamental was based on: No loss of life is acceptable (“Vision Zero,” n.d.). Road users should be protected at every turn through a better road system design. Vision Zero Los Angeles fundamental is to design a safe roadway system like Sweden, with an approach of reducing the speed limits because speed is found to be a primary factor in crashes. Research indicates that in crashes where the vehicle has higher speed experience more fatal and severe injury crashes. In Los Angeles, of total crashes since 2012 to 2015, approximately 30% crashes are speed related (Figure 2). Fatalities by mode    Between all modes of transportation in Los Angeles County, 34 percent fatal collisions account for Active transportation modes which are walking and bicycling and 53 percent account for fatal automobile collisions. Motorcycle accounts for 13 percent fatal collisions. Although the percentage of walking and biking is 34 percent, the amount of exposure is not known for people walking and bicycling.Usually roadway fatalities are normalized by 10000 Population or 100M Vehicle Miles Traveled (VMT) and when fatalities are normalized by population, the measure of overall safety can be determined. Hence the fatalities are normalized by vehicle miles traveled to measure safety per mile traveled.Many factors influence traffic deaths and injuries. Some common factors which mainly influence automobile crashes are speed, alcohol impairment, and roadway characteristics such as pavement conditions (Lee and Mannering, 2002; Aarts and Schagen, 2006; Karlaftis and Golias, 2002). Use of cell phone while driving is also a contributing factor to automobile collisions (Olson and Dewar, 2007; de Carvalho Ponce et al., 2011). Factors influencing bicycle and pedestrian crashes are relatively multifaceted. Pedestrian violation and improper turning are some factors which cause crashes amongst pedestrians and automobile and bicycle and automobile (FHWA (A) 2017). Unsafe automobile speed is also one of the factors causing fatal crashes amongst pedestrians and bicyclists. Research has indicated that at 50 miles per hour the percentage chance of pedestrian survival is only 25 percent whereas at 25 miles per hour the survival chance is 90 percent if struck by an automobile (W.A. & D.F., 1999). Some research has indicated that built environment also contributes to collisions. Some of them include schools, public transit access, grocery stores, etc. Furthermore, collisions are also influenced by socio-demographic factors like population density, employment density, age, low income etc. (LaScala et al., 2004; Rothman et al., 2014; Dai and Jaworski, 2016)Fatal Collisions by Urban-Rural areaIn year 2014, maximum number of the collisions occurred in the urban areas. Of all total collisions, approximately 90% of collisions occurred in the urban areas and approximately about 85 percent sum up to be fatal and serious injury collisions. Most of the LA county’s population works and commutes in the urban areas which explains the occurrence of collisions in the urban areas. Fatalities by Crash typeNearly half the Fatalities in LA county occurred due to incorrect Roadway Departure.  The U.S. Department of transportation defines a roadway departure crash as “a crash which occurs after a vehicle crosses an edge line or a center line, or otherwise leaves the traveled way” (“Roadway Departure Safety – Safety | Federal Highway Administration,” n.d.). Single vehicle crashes were highest in year 2015 and 2013. Although the number of crashes decreased in 2014, the crash type is consistent. This explains distracted driving phenomenon when a driver is driving alone. Speed related fatal crashes increased from 2012 to 2015 but remained nearly same for 2013 and 2014. Number of Fatal crashes involving an intersection was slightly below the number of speed related crashes. In Los Angeles county, the intersections are recognized as the most hazardous locations on the roads. This can be due to conflicting maneuvers between the automobile drivers and pedestrians and bicyclists. Collisions by ViolationOf 3102 total fatalities in 2014, 135 collisions accounted for the traffic speed violations, resulting in the most common factor for collisions. Pedestrian violation in Los Angeles County turned out to be the second highest after traffic speed violations. Alcohol impairment in bicyclist and automobile drivers accounted for 2.7 percent of total fatal collisions. Paper 2    Based on the data availability, paper 2 will further identify  road safety counter measures and test the influence of transportation modes on fatal collisions and evaluate the significance of each. ReferencesChen, L., Chen, C., Ewing, R., Mcknight, C. E., Srinivasan, R., & Roe, M. (2013). CHP-SWITRS. (n.d.). Retrieved January 25, 2018, from Highway Administration (FHWA) (A). 2017. 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