The Role of Street Trees for Pedestrian Safety

92312This research report studies the link between street trees and the gap between pedestrians\u2019 perceptions of safety and their actual safety while walking along street corridors. Prior to this report, there was little research highlighting the relationship between street trees and pedestrian safety. The research team undertook two projects to understand the role of street trees and pedestrian safety: (1) An analysis of 181 pedestrian intercept surveys across streets with varying street tree cover; and (2) A GIS mapping analysis that measured urban design variables and street tree characteristics alongside recorded pedestrian-vehicle crashes. Overall, street trees did positively impact pedestrian safety, but the impact was small and further research is needed. These findings support the work of previous research and contain relevant information for street redesign standards and planning, especially Complete Streets guidance and technical assistance. Street trees can serve as an option for applying Complete Streets principles into smaller-scale projects to improve pedestrian mobility and community livability, especially in environmental justice areas. There may also be ways to leverage street tree advocacy and streetscape redevelopment projects through existing funding programs, and promote inter-agency collaboration and public-private partnerships

Change in Mental Models of ADAS in Relation to Quantity and Quality of Exposure

69A3551747131Given the importance of mental models towards safe interaction with Advanced Driver Assistance Systems (ADAS) and the various human factors challenges regarding ADAS such as miscalibrated trust and the effect on workload, it is important to understand how different types of driving experiences and exposures affect drivers\u2019 mental models about ADAS. The objective of this study was to examine how the frequency and quality of exposure (exposure defined as driving through events or situations that have some bearing on the functions of the Adaptive Cruise Control (ACC)) affect drivers\u2019 mental models about ACC, their trust, workload, and their use of the systems as measured by their behaviors around disengaging ACC

Post-fire Damage Inspection of Concrete Structures \u2013 Phase II

In general, tunnels are designed with an abundance of safety regarding structural integrity, however, there can be uncertainty related to structural performance after a fire event. The residual condition of a tunnel after a fire is dependent on fire intensity and duration. The goal of this study is to correlate visual and material characteristics of structural and nonstructural components of tunnels with fire temperature and exposure time. This can be further related to the residual capacity of structural members in a tunnel, providing insight into safety and overall functionality. Experimental results show that the visual response of materials with heat exposure is variable and dependent on a number of factors. A wide range of materials were studied to establish a well-versed collection of data that may be used in a post-fire inspection. In addition, mechanical testing of three configurations of structural slabs exposed to different heating regimens was conducted. The influence of heat on a structural member may be complex, and was found to be minimal for the heating regimens and loading procedures applied. This work can serve as an aid for post-fire investigation by providing methods to estimate fire intensity and duration through visual observation and mechanical testing