Define the North Star metric for Maps serving commuters

Problem Statement Description

Product context: Google is a consumer technology, ads, AI, and cloud company; its products include Search, YouTube, Android, Maps, Gmail, Chrome, Google Play, Workspace, and Google Cloud.

Google Maps is used by commuters who repeatedly travel between familiar places such as home, work, school, transit hubs, and recurring errands. These users are not exploring a new destination; they care about arriving predictably, choosing the best mode or route, avoiding disruptions, and making quick decisions under time pressure.

Your task is to define a North Star metric for the commuter experience in Google Maps. The metric should reflect durable user value for commuters while being useful enough for product teams to guide prioritization across routing, traffic, transit, notifications, personalization, and reliability.

Assume the product serves a global audience across car, public transit, walking, cycling, rideshare, and multimodal commutes. The metric should be robust across different commute patterns, regions, and levels of user intent, while respecting privacy and the fact that not every commuter explicitly starts navigation every day.

The experience should consider:

- Who counts as a commuter and what commute occasions are in scope.

- The exact user action, outcome, or value moment the North Star should capture.

- The denominator: eligible users, commute sessions, commute days, or another well-defined base.

- How Google Maps would instrument the metric across navigation, passive route checks, notifications, saved places, and transit usage.

- Important cohorts such as mode of transport, geography, commute frequency, new vs. returning users, and high-disruption vs. normal traffic days.

- Guardrail metrics for safety, trust, privacy, route quality, notification fatigue, and ecosystem or business impact.

- How the metric would help teams make product decisions and detect whether the commuter experience is improving.

The goal is to propose a clear, measurable, and decision-useful North Star metric that captures the core value Google Maps provides to commuters, along with the supporting definitions and checks needed to make it reliable at Google scale.