TripEnergy uses a demand model and a vehicle model to estimate personal vehicle energy consumption for trips recorded in a travel survey. The demand model inputs travel survey data and, for each survey trip, matches a large set of possible GPS velocity histories arising from similar trips. This set of GPS trips spans the range of driving conditions that could be associated with that trip through realistic use. The demand model also produces a set of possible ambient temperatures for that trip based on the location, time of day, and day of the year on which the trip was taken. This set of velocity histories and temperatures is fed into the vehicle model, which converts them into a distribution of possible energy requirements of that trip. The vehicle model is extensively calibrated based on EPA reported test data and validated through vehicle simulation software, accounting for tractive energy consumption, conversion efficiency, and climate control auxiliary use.
Additionally, TripEnergy works to simulate travel behavior and energy consumption on a large scale. These simulation methods evaluate a large number of possible choices for each of the hundreds of thousands of separate agents active on the transportation network at any one time. Such simulations allow agents to make decisions based on the costs associated with this choice set. This functionality provides more options to the choice sets of simulated users, including more realistic options such as driving in a less aggressive, more fuel-efficient way, or purchasing a more fuel efficient vehicle.