Question

A divided multilane highway in a recreational area has four lanes (two lanes in each direction) and is on rolling terrain. The highway has 10-ft lanes with a 5-ft right-side shoulder and a 3-ft left-side shoulder. The posted speed is 55 mi/h. Previously, there were six access points per mile, but recent development has increased the number of access points to 12 per mile. Before development, the peak-hour factor was 0.95, and the directional hourly volume was 2300 vehicles with 15% heavy vehicles. After development, the peak-hour directional flow is 2700 vehicles with the same vehicle percentages and peak-hour factor.

1. What is the LOS before and after the development?

Answer 1

Step-by-step explanation:

Before: PT= 0.10, PB= 0.03 (given) ET = 2.5 ER = 2.0 (Table 6.5)

fHV= 0.847 (Eq. 6.5) PHF = 0.95, fp= 0.90, N=2, V = 2200 (given)

vp= V/[PHF⋅fHVTB⋅fp⋅N] = 1518.9 (Eq. 6.3)

BFFS = 50+5, BFFS =55 (given) fLW= 6.6

TLC=6+3=9 fLC= 0.65

fM= 0.0

fA= 1.0

FFS = BFFS −fLW−fLC–fM–fA= 46.75 (Eq. 6.7)

Use FFS=45 D= vp/S = 33.75pc/mi/ln Eq (6.6)

After: fA= 3.0

FFS = BFFS −fLW−fLC–fM–fA= 44.75 (Eq. 6.7)

Use FFS=45 Vnew= 2600 Vp= Va/[PHF⋅fHB⋅fp⋅N] = 1795 (Eq. 6.3) D= vp/S = 39.89pc/mi/ln