Formulate OR model to reduce driver backtracking

Q: Formulate OR model to reduce driver backtracking

This is a Statistics & Math interview question from Uber for Data Scientist roles. View the full question and solution on PracHub.

Q: How do I approach Statistics & Math interview questions?

Statistics & Math questions require understanding of core concepts and practice. PracHub provides solutions with explanations to help you master statistics & math interviews.

Question

Define and reduce driver ‘backtracking’ in a marketplace. First, define a quantitative backtracking metric B per driver-hour from GPS and assignment logs, and describe an algorithm to detect backtracking segments and validate them with labels; then formulate an optimization model that assigns drivers to requests and repositioning tasks to minimize expected backtracking while meeting business goals (SLA on ETA, minimum utilization, zone fairness, cap on repositioning cost). State decision variables, objective, and constraints explicitly; choose a modeling approach (e.g., time-expanded network min-cost flow with penalties or a mixed-integer program) and discuss a real-time solution method (rolling horizon, column generation, Lagrangian relaxation) and approximation quality; finally, explain offline evaluation and an online experiment to validate improvements, and how to handle demand uncertainty via robust or stochastic optimization, including a toy three-zone, five-minute-interval example to illustrate constraints.

Formulate OR model to reduce driver backtracking

Comments (0)