### LOS A:
Density is low enough that closeness of vehicle do not effect vehicle movement
### LOS E:
No usable gap between vehicles, speed is slow,, condition can easily cross over into LOS F region.
### LOS F:
Breakdown condition, number of vehicles arriving > number of vehicles leaving, speed is zero.
## Elements to evaluate LOS:
- Travel speed and travel time
- Volume to capacity ration (V/C) ratio
- Density (number of vehicles per unit length on highway, D=F/S, where S is speed and F is flow in pcph)
- Delay (at intersection, signals) If V/C =1 (level E) V/C >1 level of service is low
- Peak hour factor (PHF): The ratio between flow for entire peak hr and the maximum hourly rate of the flow during 15 minute of that hour
- Service flow = SF = V / PHF = Peak hour volume / PHF
Where = Correction factor for road width
= Correction factor for heavy vehicle
= Correction factor for driver population
F HV = 1 / ( ( 1 + Pt ( Et - 1 ) + Pb ( Eb - 1 ) + PR ( ER - 1) )
Et, Eb, ER,, Passenger car equivalent for truck, bus and recreational vehicles.
Pt, Pb, PR,, Proportion of respective class vehicles N is the number of lanes in one direction. CJ is the capacity per lane (pcphpl) |