Use Drive mode (the full-screen HUD)

Drive mode turns the recording screen into a full-screen HUD built for glances at speed: big numbers, high contrast, nothing to fiddle with.

Start a recording on the Record tab.
Tap Drive mode. The display goes full-screen, in portrait or landscape.
Drive. Lap times update as you cross the line; voice announcements can read them to you so you never look down — see Voice announcements. The speaker button at the top mutes or unmutes them.
When you're done, tap Stop and confirm Stop & save — the recording saves and Drive mode closes. To go back to the Record screen without stopping, tap the exit-full-screen icon (Exit drive mode).

Current lap time, best lap, and last lap — always, for everyone.
The slip/calibration bar and a GPS-status warning if the fix degrades.
With Pro: the projected final time for the lap you're on and your live delta to your best lap, plus mini-sector deltas as you set them. See Predictive lap time and delta (Pro).

Mount the phone where a glance costs nothing — steering-wheel hub or dash center.
The screen stays awake in Drive mode; brightness up helps in sunlight.