Traffic engineering 6 Compute the Level of Service for each

6. Compute the Level of Service for each road in the following table Road Volume V-15 Lanes Percent Trucks Percent RV Speed limit 65 50 6724 2241 3104 1035 4028 1343 8618 2873 391 1797 358 1786 50 65 5858 1953 8521 2840 3360 1120 65 7. For al of the roads in problem 6 with a Level of Service D, E, or F, what are the number of lanes that need to be added to get a Level of Service of C?

Solution

The calculations of level of service for A will be explained elobarately and remaining values will be given directly

first calculate the PHF

PHF=V/(V15*4)

PHF=6274/(2241x4)

PHF=0.75

Service flow=V15x4=2241x4=8964

Vp=V/(PHFXNXFhXFp)

Vp=6724/(0.75x3x0.9)=3287.2

the factor of correction for heavy vehicles is

Loads coming from trucks and RV=6724(2.5x7/100+2/100x2)+6724=7396 [ 1 truck=2.5 cars, 1 rv=2 vehicles]

Fhv=6724/7396=0.9

The following parameters are considered here in the level of service

Maximum density(pc/min/lane) 54

minimum speed( mi/p/h)            62

maximum V/C                             0.75

Maximum flow service rate         3320

Here all the factors are neglected except for the number of lanes which reduces the speed by 3 m.p.h

volume=2241

capacity=8964

V/C=0.75

Maximum service flow rate =V/(PHFXNXFwxFhxFp)

=3320 pc/hr/lane [ PHF=0.75 N=3 Fw=0.9]

similarly for all the lanes it is calculated by applying suitable factors

In the second part of the question consider the D

N=V(DDHV)/(PHFXMSFXFwxFhvxFp)

N=0.6x0.2x8618x8618/(24x24x0.75x4255x0.9x3)

N=2 lanes

approximately 2 lanes are required for LOS as in service D

the remaining procedure for the remaining lines is similar to this procedure