For two lane highway segments, can you calculate level of service on this section?
This example problem illustrates the computation of LOS in the
eastbound direction of a straight, 5.5-mi-long two-lane highway in level
terrain. The study facility includes a 1.5-mi-long passing lane and a 0.5-milong
passing zone.
Description: Facility analysis in level terrain
Type of Analysis: Operational analysis
The Facts
The input data for the eastbound direction of the facility are provided in the table below.
This section is composed of 5 segments: Passing Constrained (3960ft), Passing Lane (7920ft), Passing Constrained (5280ft), Passing Zone (2640ft), Passing Constrained (9240ft)
Segment, Horizontal Class, Vertical Class, Posted Speed Limit (mi/h), Directional Volume (veh/h), Opposing Volume (veh/h), Peak Hour Factor, Heavy Vehicles (%)
1 1 1 55 850 * 0.94 8
2 1 1 55 825 * 0.95 8
3 1 1 55 820 * 0.95 8
4 1 1 55 800 500 0.94 7.5
5 1 1 55 795 * 0.935 8
The facility has the following additional characteristics:
- Facility length = 29,040 ft (5.5 mi);
- No upstream passing lanes;
- Percent grade = 0%;
- Horizontal curvature = none;
- Lane width = 12 ft in all segments;
- Paved shoulder width = 6 ft in all segments; and
- Access points = 0 in all segments (for simplification of this problem, despite variation in segment volume).
Objective
Estimate the LOS in the subject direction on the two-lane highway segment, taking into account the effects of the passing lane and the passing zone.
