31.02.430 Transit demand and supply level of service standards.
The Peninsula Regional Transportation Planning Organization is recommending two measures of level of service, demand and supply, to characterize transit LOS in urban and rural areas. The following two tables summarize the recommended thresholds and point system used in determining Table 11 (Existing LOS Conditions of Transit Routes).
Transit demand LOS is measured by examining the comfort of the transit rider in terms of the availability of a seat for every passenger. Supply LOS is calculated by combining points based on the total travel time for a passenger to complete a trip by bus. This measurement includes the frequency of scheduled trips and the travel time for a bus versus a car.
In general, routes with frequent times of departure and equal or better travel times between a bus and a car are given a LOS A. Conversely, routes traveled much faster by car with infrequent service receive a lower LOS for supply, indicating a need for some improvements. A bus with very few passengers indicates a high level of service, since a passenger is guaranteed their choice of seats. Or, if a bus is filled to twice its seated capacity, requiring passengers to stand, it receives a lower demand level of service.
|
LEVEL OF SERVICE |
DEMAND LOS |
|
A |
< .51 |
|
B |
.51 – .75 |
|
C |
.76 – 1.09 |
|
D |
1.1 – 1.25 |
|
E |
1.26 – 1.59 |
|
F |
≥ 1.60 |
|
Source: Highway Capacity Manual, 1985 Notes: (1) Used for all routes. (2) A value of 1.0 indicates that there is an average of one rider per seat during peak run. |
|
|
Supply LOS |
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|
Points (2) |
Travel Time Comparison (3) |
Headway (minutes) (4) |
Points (2) |
|
1 |
< 1.1 |
U = < 16 R = < 31 |
.5 |
|
2 |
1.1 – 1.5 |
U = 16 – 30 R = 31 – 60 |
1 |
|
3 |
1.6 – 2.0 |
U = 31 – 45 R = 61 – 90 |
1.5 |
|
5 |
2.1 – 2.5 |
U = 46 – 60 R = 91 – 120 |
2 |
|
7 |
2.6 – 3.0 |
U = 61 – 75 R = 121 – 150 |
2.5 |
|
9 |
> 3.0 |
U = > 75 R = > 150 |
3 |
|
Notes: (1) Used for determining supply LOS for urban and rural designated routes operated by Clallam Transit Agency. (2) When determining LOS, points are assigned based on values for travel time comparison and minimum headway. By combining the two (2) scores, supply LOS equals: A = 1.5 points C = 3.5 – 5 points E = 7.5 – 9.5 points B = 2 – 3 points D = 5.5 – 7 points F = 10 or more points (3) A ratio of 1.0 indicates that during the peak run, travel time by bus is equal to the time it takes to drive the same route by automobile. (4) Headway is the measurement of the time between buses during the peak period. U = Urban Routes R = Rural Routes |
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The term “range of acceptability” implies setting parameters for efficient and comfortable transit travel. The following table shows two (2) types of transit service, rural and urban. Rural transit trips are characterized by better capacity and slower headway. A rural transit rider is more willing to accept reliable infrequent service over standing room only because the rural trip lengths are usually longer. Whereas, an urban transit rider is willing to stand for a short period as long as the service is frequent. Table 10 is a planning guideline for transit performance. Transit service in the unshaded area is not as desirable to the transit agency nor transit user as within the shaded target range. As per Policy No. 15.k (subsection (3)(k) of CCC 31.02.420), transit level of service should not fall below D or concurrency will have to be resolved.
|
Faster |
SUPPLY (total travel time) |
Slower |
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|
DEMAND (pass/seat) |
A |
B |
C |
D |
E |
F |
|
A (<1/2 empty) |
A/A |
A/B |
A/C |
A/D |
A/E |
A/F |
|
B |
B/A |
B/B |
B/C |
B/C |
B/E |
B/F |
|
C |
C/A |
C/B |
C/C |
C/D |
C/E |
C/F |
|
D |
D/A |
D/B |
D/C |
D/D |
D/E |
D/F |
|
E |
E/A |
E/B |
E/C |
E/D |
E/E |
E/F |
|
F (Full) |
F/A |
F/B |
F/C |
F/D |
F/E |
F/F |
|
Urban and Rural Target Range |
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|
Extension of Urban Target Range |
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|
LOS ≥ D as per Policy No. 15.k |
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