SPEED
LIMIT
55
15s
Before You Drive
Please read and accept the following before using Sentry.

⚠️ Disclaimer & Limitation of Liability

Sentry is provided "as is" for informational purposes only. Speed limit data may be inaccurate, outdated, or incomplete at any time. Always obey posted road signs and follow all applicable traffic laws.

The developers and operators of Sentry assume no responsibility for any tickets, fines, accidents, injuries, or damages that may result from using this application. You acknowledge that you are solely responsible for your driving decisions.

Do not rely on this app as your sole source of speed limit information. This app is a supplemental tool only and is not a substitute for attentive driving.

📡 Data Sources

Speed limit data is sourced from:

  • OpenStreetMap (OSM) — Community-contributed, open geographic data (© OpenStreetMap contributors)
  • TomTom Routing API — Commercial routing and speed data
  • WZDx — Work Zone Data Exchange feeds from state DOTs for construction zone information

Data may differ from actual posted speed limits. Coverage varies by region. Updates are processed regularly but not in real-time.

By clicking "I UNDERSTAND & AGREE", you agree that you have read and understood
this disclaimer and accept all terms.
Meet Sentry
Your calm, intelligent co-pilot.
Always watching the road ahead.
Never distracting you from it.
15-second advance warning
See the new speed limit coming before you reach it
Audio-first interface
Eyes on the road. Sentry speaks — you listen
Builds as you drive
Gets smarter and more accurate every trip
How should Sentry talk to you?
You can always change this later in settings.
✓
Co-pilot — Spoken word
"Speed limit changing to 45 in 12 seconds." Full verbal awareness.
✓
Subtle — Soft tones
Musical chimes for limit changes. Nothing spoken. Elegant and unobtrusive.
✓
Zen — Haptic & Visual only
Silent. Just vibrations and the on-screen animation. Perfect for music lovers.
✓
Silent Navigator — Visual only
Pure visual display. Best with CarPlay or a mounted screen.
How much should Sentry say?
More information means more awareness — but also more audio. Your call.
✓
Quiet
Only speaks up for speeding alerts and large speed limit changes (±15mph or more).
✓
Normal — Recommended
All limit changes, 15-second advance warnings, speeding alerts. Balanced.
✓
Full Awareness
All of the above plus school zone alerts, construction zones, and accuracy feedback after each change.
Permission Needed
Sentry needs your location to know which roads you're on and how fast you're going. Your location never leaves your device except to look up speed limit data.
Location — While Using App
Required for speed limit lookups
Tap the button above, then tap Allow when your browser asks.
SENTRY
READY
NEXT CHANGE IN
—
NEXT LIMIT
YOUR SPEED
—
MPH
SPEED LIMIT
CURRENT
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Settings
Alert Style
Verbosity
Speeding Alert
Alert when over by
4 MPH
0 mph (exact) 15 mph
Persistent speeding beep
Beep every 2 seconds while over the limit
Advance Warning
Warn this many seconds before
15s
5s 30s
Accuracy Feedback
Tell me how I did
After each speed limit change, say if you were early, on time, or late
Units
Voice Settings
Speech rate
How fast Sentry speaks
Slower Faster