Research Article

Development of a Residential Road Collision Warning Service Based on Risk Assessment

Figure 7

Determination of risk existence and prediction of time-to-collision (TTC): (a) is determined based on and . (b) If two spatial ranges overlap successively more than three intervals, the predicted TTC is calculated as the first overlap, and if the predicted TTC is smaller than the TTC threshold, the collision risk is regarded to exist.
(a)
(b)