Vehicle Blocking
A two terminal bus route has the following
characteristics during the evening peak period (4-6 PM):
- cycle time = 90 minutes
- layover/recovery time = 5 minutes at each terminal
- number of vehicles = 6
- headway = 15 minutes.
Develop a vehicle block summary for this time period.
[Solution Shown Below]
Solution
The easiest place to start is with the departures. Develop a table that indicates when
vehicles should depart from the first terminal.
Leave TP #1 |
4:00 |
4:15 |
4:30 |
4:45 |
5:00 |
5:15 |
5:30 |
5:45 |
Next, determine the travel time between terminals.
Cycle Time = 90 minutes
Layover/Recovery time = 10 minutes total
Travel Time = 80 minutes
Travel Time between terminals = 40 minutes
Now that we know that the travel time between terminals is 40 minutes and the
layover/recovery time is 5 minutes at each terminal, we can develop a table of arrivals
and departures for both terminals.
Leave TP #1 |
Arrive TP #2 |
Leave TP #2 |
Arrive TP #1 |
4:00 |
4:40 |
4:45 |
5:25 |
4:15 |
4:55 |
5:00 |
5:40 |
4:30 |
5:10 |
5:15 |
5:55 |
4:45 |
5:25 |
5:30 |
6:10 |
5:00 |
5:40 |
5:45 |
6:25 |
5:15 |
5:55 |
6:00 |
6:40 |
5:30 |
6:10 |
6:15 |
6:55 |
5:45 |
6:25 |
6:30 |
7:10 |
Now we can hook the trips together and form the initial vehicle blocks.
Vehicle Block |
Leave TP #1 |
Arrive TP #2 |
Leave TP #2 |
Arrive TP #1 |
1 |
4:00* |
4:40 |
4:45 |
5:25 |
2 |
4:15* |
4:55 |
5:00 |
5:40 |
3 |
4:30* |
5:10 |
5:15 |
5:55** |
4 |
4:45* |
5:25 |
5:30 |
6:10** |
5 |
5:00* |
5:40 |
5:45 |
6:25** |
6 |
5:15* |
5:55 |
6:00 |
6:40** |
1 |
5:30 |
6:10 |
6:15 |
6:55** |
2 |
5:45 |
6:25 |
6:30 |
7:10** |
* Vehicle enters service
** Vehicle leaves service
Now we can create the final block summary.
Vehicle |
Time Block |
Time in Service |
1 |
4:00 – 6:55 |
2:55 |
2 |
4:15 – 7:10 |
2:55 |
3 |
4:30 – 5:55 |
1:25 |
4 |
4:45 – 6:10 |
1:25 |
5 |
5:00 – 6:25 |
1:25 |
6 |
5:15 – 6:40 |
1:25 |
Total |
|
11:30 |
|
