Driving or walking on, or across, a roadway is less safe in darkness than in a lighted area, due to the reduced visibility of hazards and pedestrians. Though the number of fatal crashes occurring in daylight is about the same as those that occur in darkness, only 25 percent of vehicle-miles traveled occur at night. Because of that the nighttime fatality rate is three times the daytime rate, as illustrated in Figure 1a. Figure 1b shows the difference in the number of fatal crashes on lit and unlit roadways.
Roadway lighting is a proven safety countermeasure. The positive safety effects of lighting have been documented in various reports and publications. For example, an FHWA/AASHTO international scan documented (1) that many countries showed a 20 to 30 percent reduction in the number of crashes when lighting was installed. More recently, the FHWA Signalized Intersection Informational Guide (3) reported that adding lighting can reduce nighttime crashes by 50 percent and reduce fatal crashes by 43 percent. There have been many other studies that document similar safety benefits of lighting.
For example, in looking at the impact of highway lighting on all roadway types that previouslyhad no lighting, for nighttime injury crashes, the HSM reports that research has shown a resultantCMF of 0.72 (showing that there would be a reduction of 28 percent in nighttime injury crash types). So if the expected average crash frequency is 10 injury crashes/year for a no-lightingcondition, then after implementation of a highway lighting system one would expect 10 X 0.72 CMF = 7.2 injury crashes/year.
The Transportation Association of Canada Guide for the Design of Roadway Lighting includes a warranting system for intersection lighting. The warranting system is based on geometric, operational, environmental and crash factors. The critical factors determining the need for illumination are traffic volumes and night-time crashes. The warrant point score indicates whether full intersection lighting, partial lighting or delineation lighting is needed. Full intersection lighting denotes illumination covering an intersection in a uniform manner over the traveled portion of the roadway. Partial lighting is the illumination of key decision areas, potential conflict points, and/or hazards in and on the approach to an intersection. The illumination of vehicles on a cross street or median crossing, or lighting that marks an intersection location for approaching traffic, is referred to as sentry or delineation lighting.
Narrative: At the above time, date, and location the victim was discovered deceased inside of his yellow 2-door, 1977 Honda Civic which was discovered crashed in a wooded area of the median. It was originally believed the victim died from injuries sustained in the auto crash; however, it became apparent the victim was shot while driving southbound on Crandon Boulevard and crashed into the wooded area of the median as a result of being shot. The victim was employed by the Key Biscayne Tennis Association as a tennis professional who provided tennis lessons. 2b1af7f3a8