Yellow to Green: Optimizing School Bus Routes to Reduce the Carbon Footprint of Local High Schools

Date and Time: Thursday: 10:30 AM - 12:00 PM
Location: Kavli Auditorium

 

Grace Yan, 

PRESENTATION DESCRIPTION

The transportation sector is the largest source of greenhouse gas emissions, making up 29% of US emissions with school buses as a significant contributor. While switching to electric buses may be on the horizon, the transition is expensive and not currently feasible for most public school districts. This study proposes a zero-cost solution to reduce the environmental impact of the Monongalia County Schools’ bus system through route visualization and optimization. The study focused on all thirty routes of the largest high school (Morgantown High) in Monongalia County since it encompassed the largest geographical area and over three times as many buses as other local high schools. Data was collected from the county website where official publications of bus stops, times, and routes were posted.

All 388 bus stops across 30 routes were plotted in a map (Figure 1) to extract the GPS coordinates for each bus stop, or waypoint. After the coordinates were obtained, HTTP requests were utilized to employ the Google Maps’ Python library to optimize the routes. The library’s state-of-the-art routing algorithms employ machine learning, crowd sourcing, satellites, and other methods to optimize for time, distance, real-time traffic conditions, and more. Comparisons between the travel distance and time before and after optimization of all 30 bus routes were conducted. Greenhouse gas emissions for each route were calculated based on travel distance and diesel fuel emission data.

While some of the existing routes were already well optimized,
others had stops that could be reordered for shorter distances and
travel time. Optimizations for a specific bus route are displayed in Figure 2 as an example to visually present the results. Reordering the stops within the route could save 2.9 miles and 7.1 minutes for this particular route.

The graphs in Figure 3 show savings in distance and duration for each of the 30 buses. Overall, the optimizations could save a combined 76.4 miles and 139.2 minutes each day (5.4% and 5.1% respectively). By only reordering the stops, a significant number of miles can be saved every day and in turn, save time and money on fuel and maintenance costs. The optimization will be able to save $10,017 per year on fuel alone (according to current diesel prices at $5.10 per gallon). The original daily CO2 emissions of all 30 buses is approximately 2.0 metric tons. Every year, the optimization will prevent 20 metric tons of CO2 from being released into the atmosphere, the calculated equivalent of taking 4 cars off the road for one year.

After the initial case study of one school, a web platform was created to simplify this process for other districts. By entering a list of bus stop addresses, individuals are able to quickly optimize their routes and gain valuable insights on the original and optimized routes. This project was presented to the county and state Directors of Transportation and a pilot study is being conducted in the 2022-23 school year.

SPEAKER BIOGRAPHY

Grace Yan is a junior at Morgantown High School in Morgantown, West Virginia. She has been a bus rider since she was in kindergarten and is very passionate about the environment. These interests prompted her to do research on bus route optimization to help reduce the carbon footprint of school buses. She hopes to be able to raise awareness for air pollution and climate change with her work. She is very interested in the intersection between math and science.

PRESENTATION FILE