The purpose of this project was to find a way to improve the efficiency of the Washington University Circulator shuttle. The circulator shuttle (or “circ”) is a free shuttle service offered to students of Wash U in order to quickly and easily travel around campus. As students and former circ riders, we know how convenient and helpful the circ is, as well as the inefficiencies it has, first hand, so we set out to solve this problem and improve the circ for the students who rely on it.


Map of the current Circulator route

Current Circulator Route from the Wash U app

The circ follows a set route around the Danforth campus that takes it from the South 40 to the Village and back again. The map to the left is taken from the Wash U app, and shows the route of the circ as well as the stops it makes. The listeds tops for the circulator are: Millbrook garage, in front of Brookings quad, in front of Lee hall, at the South 40 Clocktower, outside Mallinckrodt hall, and at the Skinker station. One complete trip through the route takes approximately 20 minutes, with some stops requiring the full 20 minutes before another shuttle comes. This timing, along with delays in service, means that if a student misses the shuttle or is otherwise unable to board that student can have upwards of 20 minutes until the shuttle comes back around, an eternity when trying to get to class on time. Even when timing is not an issue the circ is not perfect. Each shuttle holds 35 passengers, including standing room, and it is not uncommon to see 20+ passengers waiting at some of the stops. This abundance of passengers leads to situations where students who are waiting in line cannot board the circ, which can in turn lead to problems with timing as discussed earlier.

Our senior design project aims to alleviate these issues using queuing theory to model the circulator and its passengers. As we improve the circ service, more students will utilize it, increasing the strain on the system and testing the limits of any solution. The challenge we face is to design a system that not only solves the current problems, but one that can handle both the challenges of today as well as those of tomorrow.


Casey Nordberg
ESE Undergraduate
Natasha Zachariades
ESE Undergraduate
Maomao Lai
ESE Undergraduate
Dr. Zachary Feinstein
ESE Department Professor