Estimate Lifetime Hours a Person Spends Waiting at Intersections and Traffic Lights

Estimate how much time, in total, a typical person spends at traffic intersections across their whole life. ```hint Make one trip the unit Work out what a single trip loses at intersections first, then think about how the number of trips changes from childhood to old age. ``` ### Clarifying Questions - Does "an intersection" mean every intersection the person passes through, or one specific intersection, such as the one nearest their home? - Should I count time spent as a pedestrian and as a passenger, or only time spent driving? - Should I count only time spent stopped at red lights and stop signs, or also the seconds spent moving through the intersection? - Should I model a typical resident of a car-dependent US metro area, or a global average person? ### What a Strong Answer Covers - A precise definition of what counts as time at an intersection and which travel modes are included - A clear equation that breaks the total into trips, intersections per trip and average delay per intersection, segmented by life stage - Labeled, defensible assumptions with clean arithmetic and correct unit conversions - A sanity check against total daily travel time, and a range showing which assumption moves the answer most ### Follow-up Questions - How would your estimate change for someone in a dense city who mostly walks, compared with a rural driver? - Which single assumption is your answer most sensitive to, and what data would you use to pin it down? - How could a navigation product such as Google Maps use an estimate like this, for example in routing or arrival-time predictions?