Determine the fatal crash and total crash rates (per 100 million VMT) for each year and for the three-year period. Comment on and qualify the results as necessary.

Question

A 5.4-mile segment of highway has the following traffic and safety data:

Answer 1

First, determine annual vehicle-miles of travel:
2005 VMT = (15,950 veh/day)(365 day/yr)(5.4 mi) = 31,437,450
Similarly, 2006 VMT = 32,521,500 and 2007 VMT = 34,393,950
Then, determine fatal crash rates:
2005 fatality rate = 4 fatalities / 31,437,450 VMT = 12.7 fatalities / 100 MVMT
Similarly, 2006 fatality rate = 3.1 fatalities per 100 MVMT and
2007 fatality rate = 8.7 fatalities per 100 MVMT
Across all: RMVMF = (4 + 1 + 3 fatalities / 98,352,900 VMT) = 8.1 fatalities /
100 MVMT
Similarly, determine total crash rates:
2005 crash rate = 35 crashes / 31,437,450 VMT = 111.3 crashes / 100 MVMT
Similarly, 2006 crash rate = 98.4 crashes per 100 MVMT and
2007 crash rate = 87.2 crashes per 100 MVMT
Across all: RMVMT = (35 + 32 + 30 crashes / 98,352,900 VMT) = 98.6 crashes /
100 MVMT
Crash rates are slightly below the national average. Fatality rates are well
above the national average; however, the fatality rates are based on a small
sample size of only eight fatalities.