* Corresponding author: khondoker.billah@utsa.edu Urban Intersections and Traffic Safety in the City of San Antonio Qasim Adegbite, Khondoker Billah * , Hatim Sharif, and Samer Dessouky Department of Civil and Environmental Engineering, University of Texas at San Antonio, San Antonio, TX 78249 Abstract. Intersections are high-risk locations on roadways and often experience high incidence of crashes. Better understanding of the factors contributing to crashes and deaths at intersections is crucial. This study analyzed the factors related to crash incidence and crash severity at intersections in San Antonio for crashes from 2013 to 2017 and identified hotspot locations based on crash frequency and crash rates. Binary logistic regression model was considered for the analysis using crash severity as the response variable. Factors found to be significantly associated with the severity of intersection crashes include age of driver, day of the week, month, road alignment, and traffic control system. The crashes occurred predominantly in the high- density center of the city (downtown area). Overall, the identification of risk factors and their impact on crash severity would be helpful for road safety policymakers to develop proactive mitigation plans to reduce the frequency and severity of intersection crashes. 1 Introduction Road intersections are one of the most dangerous locations in a roadway network as they are the convergent spots for vehicles and people moving in opposite paths. They often impose a major responsibility on road users to make an informed decision on when to cross the road to forestall unsafe situations. This part of the road has one of the most complicated traffic situations that motorists come across. Negligent high speeding drivers who often disregard traffic signals further compounds the problem [1]. In the United States, about one-quarter of road fatalities and about half of all traffic injuries over the last several years are attributed to intersections [2]. Intersection crashes account for more than 40% of all crashes in the United States [3]. A study examining the characteristics of 787,236 motor vehicle intersection crashes from 2005 through 2007, as listed in the dataset from the National Motor Vehicle Crash Causation Survey [4], showed that 96% of intersection crashes had critical factors attributed to drivers and less than 3% had critical factors were related to the vehicle or environment [4]. Ensuring safety of road intersections is a complicated issue and cannot always be mitigated by barely changing/adding signals and signs. A more sustainable solution can be achieved by a national comprehensive program of improved pedestrian safety and vehicle intersection management [4]. Proper identification of intersections associated with high crash rate is vital to reduce future crash occurrence. As of 2016, Texas has the highest number of fatal crashes in the United States; 3,406 crashes resulting in 3,776 deaths in that year. This is over 5% increase over 2015 figures of 3,226 fatality crashes and 3,582 deaths. There was also a 5.09% increase in total miles traveled in 2016 (271.263 billion) compared to 2015 (258.122 billion). Over 800 of these deaths occurred at intersections or were related to an intersection. Bexar County, where San Antonio is located, had the 3rd highest totals in Texas in 2016, with 52,633 crashes and 220 deaths because of the crashes [5]. Several factors contribute to intersection crashes including driver related factors, vehicle related factors, environment and road-related factors. Driver errors are mostly human related factors which include those committed while under the influence of alcohol, or otherwise violating traffic rules and regulations, and errors committed due to lack of training. Road-related factors include traffic characteristics e.g. traffic volume, geometric design of the intersections, traffic control measures, state of line markings and signage, and surface and light condition [6]. Environment-related factors, such as weather conditions and natural lighting conditions are mostly considered external to human factors as they are beyond human control. Another identified problem is the difficulty of many drivers in judging gaps in high-speed traffic situation on a divided highway with many lanes, as well as drivers trying to do left-turn or cross into a divided highway [7]. Human factors are the main cause of over 90% of car crash incidents [8]. The viewpoint of science of safety has shifted due to the evolution of data science. The focus is now on data and analysis rather than sole dependence on standards as stated in FHWA’s Highway Safety Improvement Program Manual. For data analysis and safety consideration, three to five years of crash data is the most common time frame for good data representation. Less than five years data might be good enough for some cases. But a smaller sample size does not adequately represent the data in general and might require statistical adjustment [9]. The need for field assessment of intersection spots has been identified as a major activity © The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/). MATEC Web of Conferences 271, 06003 (2019) https://doi.org/10.1051/matecconf/201927106003 Tran-SET 2019