Road Safety Professional (RSP) Level 1 Practice Exam

Stochastic factors describe the randomness in crash outcomes. In real driving, even with similar conditions, small, unpredictable differences—like a driver’s split-second reaction time, slight variations in tire grip, or an unexpected movement by another road user—lead to different results. Because these elements can’t be predicted with certainty, they’re described as random or unpredictable.

Deterministic factors are the ones where a known cause-and-effect relationship exists if you know the inputs. Controllable roadway design refers to aspects that engineers can modify to influence outcomes. And saying there’s no injury isn’t about the nature of the factors; it’s simply a possible outcome, not a description of randomness.