Santa Clara University


Modeling the Future of Transportation

Rachel He
Professor Rachel He models traffic scenarios in her office at SCU.

Transportation engineering is a growing field that has the potential to improve the quality of urban life in a number of different ways. A division of civil engineering, this field focuses on reducing traffic congestion, alleviating noise and airborne pollutants from vehicle emission, and planning for safe evacuation in times of disaster, whether natural or human-caused.

But, as Professor Rachel He points out, transportation engineering differs from other disciplines of civil engineering in that “we’re dealing with people, and their driving behaviors are not easily predicted and modeled. We can model mechanical properties; we can model structural loads, but the randomness of human behavior defies total predictability.”

To model different scenarios, Dr. He uses traffic simulation computer software. “On the computer, we can not only build large urban transportation networks with freeways, interchanges and major arterials, but also study a single intersection on a local street,” she said. Integrating the fixed attributes of the roadway—number of lanes, directions, and slope grades—is the easy part; accounting for the uncertainties—traffic conditions, day of the week, time of day, and weather conditions that all affect a driver’s decision-making—is what makes the work interesting.

As the computer simulation models are becoming more mature, the research is becoming more viable, and Professor He is increasingly motivated to bring undergraduates into the field. Each year she advises several students who choose transportation simulation modeling as their senior capstone projects. “I want our students to have an early exposure to traffic simulation modeling,” she said. “Alleviating congestion, reducing environmental impact, and ensuring safe evacuation in times of disaster are as much a part of our survival as structural engineering.”