Travel time is an estimate for a particular origin, destination, mode, departure time, and routing preference. A prompt must not present a cached number as current traffic. The application should attach generation time, validity window, distance unit, and any fallback status to every route leg. If an element has no route or the provider used a fallback method, mark it for review rather than inventing a duration. For a multi-stop plan, retrieve the needed pairwise legs and check that all origins and destinations correspond to verified stop identities. The model can explain trade-offs but should not fabricate matrix cells.
Make this comfortable
Location prompts: label travel estimates and stale matrices
Operational case
Quartz requests a driving matrix for three verified jobs and depot start at the planned morning departure. The result gives 22 minutes from depot to J-47, 18 minutes from J-47 to J-52, and 31 minutes from J-52 to J-71. A saved matrix from the previous week lists 16 minutes for the last leg; the prompt rejects that older cell for today's plan. If the current J-52 to J-71 element is missing, the route remains provisional even though the other two legs are available.
Mode: driving; departure: planned morning instant.
Fresh legs: depot→J-47 22 min; J-47→J-52 18 min.
Fresh leg: J-52→J-71 31 min.
Old J-52→J-71 value: 16 min -> do not substitute.
Missing current element -> provisional plan.Performance and operating cost
A complete matrix for S stops can require O(S squared) origin-destination elements, while evaluating one fixed sequence needs only O(S) legs. Request only the combinations required by the planner and retain a matrix ID for review. Refreshing estimates adds network latency and possibly usage cost, but avoids a false on-time claim. A routing service may return estimates with uncertainty; the prompt should preserve that status instead of turning a prediction into a guaranteed arrival.
Common Mistakes
- Do not present a week-old leg as current traffic.
- Do not fill a missing matrix cell with an invented time.
- Do not call an estimated arrival a guaranteed arrival.
Connected lessons
- Prompt engineering applications
- Prompt Engineering
- Retrieved evidence: reconcile versions and conflicting facts
- Research prompts: bind claims to a date and evidence record
- Capacity prompts: check units, headroom, and a failed worker
- Location prompts: resolve ambiguous addresses before routing
- Location prompts: validate coordinates, units, and precision
- Location prompts: compute stop-window feasibility before recommending
- Location prompts: review the map and gate dispatch effects
- Project: review a Quartz field-service route
- Location-aware prompt decisions
prompt engineering
location dispatch