10. Five roadway sections (A thru E) were identified as high accident locations
ID: 1714601 • Letter: 1
Question
10. Five roadway sections (A thru E) were identified as high accident locations based on the use of several identification methods. All locations are on two lane county roads with 10 to 11 feet lanes and shoulders less than 3 feet wide. All sections are on rolling terrain with moderate horizontal curvature. The statewide average accident rate for this class of roadway in Superior County is 3.5 ACCS/MVM. (worth 16 points) The sections have the following information: Location Section Length AADT PDO Total No. of No. of Years (miles) 0.8 1.2 3.4 2.2 1.6 4200 3500 1750 2400 3000 12 15 35 24 12 Accidents 15 21 43 27 27 2 2.5 1.5 Which section is most critical?Explanation / Answer
AADT is the annual average daily vehicle
Roadway section accident rate is given by the formula:
Rs = (A / VMT)
where,
Rs = roadway section accident rate in accidents per million veh-mi of travel
A = annual number of accidents = Total number of accidents / No: of years
VMT = million annual vehicle mi of travel = (AADT x No:of years x 365 days x section length in miles) / 106
Severity index is given by the formula:
SI = No: of fatalities / Total number of accidents
where, No: of fatalities = Total no:of accidents - PDO
PDO is the Property Damage Only
These values are calculated for each section in the table below.
Eventhough the roadway section accident rate is highest for section D, severity index is highest for section E.
Thus most critical section is section E.
Location VMT A RS No:of fatalities Severity index A 3.6792 5 1.36 3 0.2 B 3.066 10.5 3.42 6 0.29 C 5.429 17.2 3.17 8 0.19 D 2.8908 18 6.23 3 0.11 E 5.256 9 1.71 15 0.56Related Questions
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