Road Safety Engineering - Problems

 ROAD SAFETY ENGINEERING PROBLEMS

• Accident Rate per Kilometer

        Number of accidents of all types per km of each highway and street classification.

        R = A/L

        R = total accident rate per km for one year,
        A = total number of accident occurring in one year,
        L = length of control section in km

• Death rate based on population
  
  Number of traffic fatalities per 100,000 populations.
  
  R = (B × 100000 )/ P
  
  R - death rate per 100,000 population,
  B = total number of traffic death in one year and
  P = population of area

• Death rate based on registration

        Number of traffic fatalities per 10,000 vehicles registered.

        R = (B × 10000) / M

        R - death rate per 10,000 vehicles registered,
        B - total number of traffic death in one year
        M - number of motor vehicles registered in the area 

• Accident involvement Rate

        Numbers of drivers of vehicles with certain
        Characteristics who were involved in accidents per 100 million vehicle-kms of travel.

        R = (N × 100000000)/V

        R - accident involvement per 100 million vehicle-kms of travel,
        N - total number of drivers of vehicles involved in accidents during the period of investigation
        V - vehicle-kms of travel on road section during the period of investigation

• Accident Rate based on vehicle-kms of travel

        Number of accidents per 100 million vehicle km of travel.

        R = (C × 100000000)/V

        R = accident rate per 100 million vehicle kms of travel,
        C = number of total accidents in one year and
        V = vehicle kms of travel in one year

PROBLEM

The Motor vehicle consumption in a city is 5.082 million liters, there were 3114 motor vehicle fatalities, 355,799 motor vehicle injuries, 6,721,049 motor vehicle registrations and an estimated population of 18,190,238. Kilometer of travel per liter of fuel is 12.42 km/liter. Calculate registration death rate, population death rate and accident rate per vehicle km.

Solution: 

 Approximate vehicle km of travel = Total consumption of fuel × kilometer of travel per liter of fuel                                                             =5.08 × 106 × 12.42 = 63.1 × 106 km.

Registration death rate can be obtained from

R = (B × 10, 000) /M

R is the death rate per 10,000 vehicles registered, 

B (Motor vehicle fatalities) is 3114, M 

(Motor vehicle registered) is 6.72 × 106.

Hence

R =(3114 × 10000) /6.72 × 106 = 4.63

Population Death Rate can be obtained from the equation.

R =(B × 100, 000)/P

Here, R is the death rate per 100,000 population

B (Motor vehicle fatalities) is 3114, 

P(Estimated population) is = 18.2 × 106.

R =(3114 × 100000)/18.2 × 106 = 17.1

Accident rate per vehicle kms of travel can be obtained from the equation below as:

R =(C × 100, 000, 000) / V

Here, 

R is the accident rate per 100 million vehicle kms of travel, 

C (total accident same as vehicle fatalities) is 3114

V (vehicle kms of travel) is 63.1 × 109.

R =(3114 × 100 × 106 )/63.1 × 109 = 4.93