Arterial roadway energy/emissions estimation using modal-based trajectory reconstruction

Trajectory-based vehicle energy/emissions estimation for signalized arterials using mobile sensing data

“…To explicitly describe the behavior of queued vehicles around signalized intersections, their trajectories are decomposed into small segments -each segment represents one driving mode. This process is called modal decomposition, which was introduced in Yang et al (2011) and is adopted and extended in this paper. At signalized intersections, the trajectories of queued vehicles can be decomposed into five modes, i.e., cruise before deceleration (T 1 cruise Þ, deceleration (T decel ), idle (T idle ), acceleration (T accel ), and cruise after acceleration (T 2 cruise Þ.…”

“…In Yang et al (2011), a free-flow vehicle is assumed to travel at a constant speed, i.e., the free-flow speed. The time-speed profiles for such vehicles are simply straight lines.…”

“…To incorporate such impacts into the trajectory-based emission model, the acceleration process certainly needs to be considered. In Yang et al (2011), the acceleration rate is assumed to be constant. Such assumption may not be realistic since the level of acceleration for vehicles at different traffic states may not be the same.…”

“…The conventional way to model the cruise mode is to assume that a vehicle will travel at the free-flow speed (Li et al, 2009;Yang et al, 2011;Skabardonis et al, 2012). In essence, such assumption is usually too ideal and may lead to under-estimation of energy/emissions.…”

“…Uniform deceleration and state-dependent acceleration processes are considered in order to provide a more realistic estimation of vehicle trajectories. The proposed method therefore overcomes the aforementioned limitations in Yang et al (2011), that is, to incorporate detailed vehicle trajectories (especially the state-dependent acceleration process), and to estimate fuel consumption/emissions of the entire traffic flow. Inspired by the modal decomposition idea in Yang et al (2011), the reconstructed vehicle trajectories in the time-space domain are decomposed into different driving modes and then transformed into the time-speed domain.…”