Research Article

Crash Frequency Minimization with Severity Mitigation in Road Geometric Design Using Chance Constraint Programming Optimization

Table 3

Descriptive statistics of crash frequency-related variables.

ModelVariableDescriptive value (std. dev.) (min) (max)

25CBDAverage annual crash frequency for each direction0.38 (0.72) (0) (4)
Average of directional average daily traffic per lane3009.45 (1520.898) (1100) (7200)
Percentage of each direction on M st from 11th st to Centennial Mall st13
Percentage of each direction on N st from Centennial st to 9th st20
Percentage of 10 ft lane width for each direction77

35NCBDAverage annual crash frequency for each direction1.29 (2.08) (0) (23)
Average of directional average daily traffic per lane5989.56 (2630.39) (1250) (14846.69)
Percentage of each direction on 27th st between Nebraska highway and Cornhuskers highway11
Percentage of each direction on 40th st between Van Dorn st and Pioneers Blvd1
Percentage of 1 lane for each direction61
Percentage of the one way road69
Percentage of 9 ft lane width for each direction18
Percentage of 10 ft lane width for each direction38
Percentage of 11 ft lane width for each direction31

40 MPHAverage annual crash frequency for each direction1.15 (1.48) (0) (9)
Average of directional average daily traffic per lane5858.79 (2721.52) (2300) (19480.37)
Average segment lengths0.41 (0.27) (0.11) (1)
Percentage of each direction on Cornhusker highway between N 29th st and N 33rd st2
Percentage of each direction with average daily travel in vehicles per lane less than 1000094
Percentage of 2 lanes for each direction72
Percentage of 10 ft lane width for each direction39
Percentage of 11 ft lane width for each direction23

45 MPHAverage annual crash frequency for each direction0.8 (1.21) (0) (10)
Average of directional average daily traffic per lane5291.65 (2223.07) (862.5) (11650)
Average segment lengths0.52 (0.34) (0.09) (2)
Percentage of each direction on 27th st between Old Dairy rd and Kmart Dr2
Percentage of each direction on Nebraska highway from S 33rd st to S 27th st1
Percentage of 11 ft lane width for each direction41