In routing special-education students in an urban environment, the students must be picked up at home and delivered to selected schools which meet their specific educational needs. This is called a many-to-several routing problem. (Many students are picked up in one bus and transported to several distinct educational programs.) In addition to this problem structure, special sequencing restrictions and route duration limitations exist. Heuristics can achieve significant savings for both route distance and route duration, and a shuttle system is also found to be effective.
The Tulsa, Oklahoma public school system determined bus routes for about 850 special education students in 66 schools. The students not only attend special schools, but also need special buses due to a variety of disabilities. For example, different types of buses are needed to accommodate students in wheel chairs. Special education students within the same neighborhood often attend different schools, thus further complicating the problem. Route planners were constrained by a 45 minute travel time limit and school hours varied from school to school. Three strategies were applied to solve the problem of routing the special education buses. Bus to school, where one bus picks up all students going to the same school. Home to school to school, where students took a bus to a nearby school and were transferred onto another bus for the duration of their ride. Finally, school to meeting point to school, where students were shuttled to a vantage point and picked up by another bus for the duration of the trip. Using routing methods, the Tulsa public school system was able to save time and money, although drivers were sometimes unhappy that wages were cut due to fewer hours of driving. Based on sample studies, it was estimated that the routing algorithms could reduce miles traveled by almost 11% and time spent in route by almost 16%. This would translate into an estimated $50,000 to $100,000 in savings if the routing algorithms were used for all special-education busing in Tulsa.