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

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