Fixed-route scheduling

Introduction

Focus on scheduling for an existing or already planned route. Does not address methods for developing a new route from scratch.

Basics

Ascertain basic qualities and values: Frequency, consistency (clockface scheduling), connections with other services. Begin with basic calculations: Based on free-flow speed limits, what is the time end-to-end? Ascertain timepoints if not already done (divide route into roughly equal points, maybe 4 timepoints approximately 10 minutes apart). Run trial operations collecting data for all days and times of service. Determine how much variation is between peak and off-peak (can affect how many vehicles needed to maintain headways)

Putting it all together

Adding up times between timepoints. Be sure to allow time for boarding, hopefully based on real or projected ridership. Estimate delay if needed, use an agency average, etc. Add recovery or layover time. Good rule of thumb is 10% of round-trip time. Lay out route in a table with departures based on target frequency.

Usually good to test draft product to watch for hiccups.

Some revision may be needed. Small amounts of slack time in the middle of a route may be necessary to account for travel variations. If planning flexible transit route, need to incorporate slack time for deviations but not so much that a no-deviation trip isn't sitting around waiting exceptionally long times.

Agency Variation

The type of agency and minimum service level vary tremendously between very large cities and small urban areas. Small urban areas may only support hourly or 30-minute headways where in a large city the maximum headway may be 10 minutes or less.

Agencies working with long headways and multiple routes need to carefully consider connections and probably allow greater slack time.

Adjusting factors

Sometimes once everything is factored in, a route appears inefficient. For example, a route in free-flow can do a round trip in 40 minutes, but when all other factors are added the run time is 65 minutes. It may be desirable to get the route down to 60 minutes or less.

Examine: passenger stop delay (boarding, alighting), average traffic speed, signal delay, geographic factors - are buses slowly crawling through tight areas that could be avoided, etc. Use various strategies to reduce. Avoid making route so tight only the best/senior operators are capable of handling it safely. Keep operations administration involved.

Runcutting and operations

SEPARATE ARTICLE? Once a route is scheduled (or rescheduled), service needs to be segmented into blocks of work.

Factors

Federal, state, and agency labor policy. How many hours can employees work, how is work assigned (seniority, etc.)