Product design case: improving how pedestrians and drivers share a crosswalk

You are asked to design the crosswalk where people on foot cross a road that vehicles also use. Walk through your approach. ```hint Look past the stripes List everyone who uses or is affected by a crossing, then ask which of them today's painted lines and walk signal serve worst, and at which moment of the crossing. ``` ### Clarifying Questions - Where is the crosswalk: a signalized intersection downtown, a mid-block crossing on a busy multi-lane road, or a quiet residential or school street? - Is the main goal pedestrian safety, accessibility, traffic flow, or lower cost for the city? - Who is the customer: the city transportation department that buys and maintains the crossing, or the pedestrians and drivers who use it? - Can we change the physical street (curbs, islands, lighting), or only signals and markings? ### What a Strong Answer Covers - A stated goal and a chosen setting and user segment, with the reasoning - The needs of different users: pedestrians of varying mobility, vision and age, turning drivers, cyclists, and the city that owns the road - Concrete solutions across markings, signals, physical design and technology, prioritized by impact and cost - Success metrics that work even though crashes are rare, with guardrails such as vehicle delay and cost - Trade-offs and risks, including maintenance, false confidence and traffic standards ### Follow-up Questions - Your design adds a sensor that extends the walk phase for slow pedestrians. What could go wrong, and how would you know it is working? - The city can afford only one improvement across many crossings this year. Which one do you pick, and how do you justify it? - How would your design change for a crossing outside a primary school?