Continuous approximation models for mixed load school bus routing

•Continuous approximation models are useful for strategic analysis of mixed load school bus routing.•The benefits are greater when many bus stops are shared and for schools close together.•Mixed school bus routing is likely to be more advantageous in rural or semi-rural districts.

School bus routing is a complex and expensive transportation problem for many public school districts. Typical school bus routes serve a single school, but mixed load school bus routes carry students for more than one school at the same time. A mixed load policy reduces the number of stops and distance to pick up and drop off children, but it can increase travel distance by visiting multiple schools. This paper provides a general strategic analysis using continuous approximation models to assess the conditions under which mixed loading is likely to be beneficial. We also present a case study for a semi-rural Missouri school district to illustrate the application of the models in practice. Results show that mixed load routing is more beneficial for larger districts, when a large percentage of bus stops are shared by students of different schools, and when schools are closer together.