Reaction-Time Safe Ride Check

The Safe Ride Check is a short reaction-time test the rider takes before unlocking during a configurable late-night window. It is designed to encourage safe decisions - it is not a sobriety or DUI test, and Levy frames it carefully both in-app and in the rental agreement.

What the rider does

1. Late-night unlock attempt (default window: 22:00 to 04:00 local).
2. The app launches a 5-round tap-the-dot mini-game. Each round spawns a dot in a random screen position; the rider taps it as fast as they can.
3. Each round records a reaction time in milliseconds, or a "miss" if the rider does not tap inside the 3-second timeout.
4. After 5 rounds the app computes the median reaction time and miss count.
5. Pass: median reaction time < 450ms, fewer than 2 misses.
6. Fail: rider sees a 30-minute unlock cooldown plus an "Are you safe to ride?" prompt with an Uber-style "Call a friend" CTA.

Pass thresholds

All are per-subaccount editable at Settings > Safe Ride Check.

Trigger window

The night window wrap (10pm to 4am crosses midnight) is handled in isWithinNightWindow() in src/lib/rider-score/reaction-test.ts and is unit-tested. You can also leave the window open all day if you really want, though we do not recommend it - the fail rate of a sleepy rider mid-afternoon is high enough to be unfair.

What happens on fail

A single fail:

• 30-minute unlock cooldown on this rider's account.
• The cooldown UI surfaces the time-remaining and a "Try again" button.
• No score penalty.
• No score_audit_log row, because no action was taken against the rider's tier.

Three fails in 24 hours opens a step-6 temporary lockout in the intervention ladder. This is the cross-link to the ladder - the reaction test is one of the inputs that can escalate a rider into a lockout, alongside score-based triggers.

What happens on pass

• The rider unlocks normally.
• A reaction_tests row is recorded with passed=true, the median, the miss count, and the trigger.
• No effect on score or pricing.

Cooldown logic

The evaluateAttempts() kernel is unit-tested. The rules are:

reaction_tests row:
  median_reaction_ms  - median of all rounds
  miss_count          - misses (timeout >= 3s)
  passed              - bool from pass criteria
  trigger             - 'nighttime' | 'appeal' | 'random'
  cooldown_until      - now + 30 min on fail

A rider whose cooldown_until is in the future is blocked from ride start by the pre-unlock gate. The block is reported as reason='reaction_cooldown'.

When else the test fires

• Nighttime trigger (default): every unlock attempt inside the configured night window, if the rider has not passed within the last N hours (default 6).
• Appeal trigger (optional): an operator can require a Safe Ride Check before approving a step-6 lockout appeal. This is off by default.
• Random trigger (optional): a random subset of all unlocks (any time of day) get the test. Default 0%. Use this to catch impairment outside the night window - keep it low (1-2%).

Privacy and what we do not do

• We do not log who the rider was talking to or what app they came from.
• We do not record the rider's screen, camera, or microphone.
• We do not share reaction-test results with insurers in identifiable form.
• We do not share results with law enforcement except by warrant.
• The 30-minute cooldown is a cooldown, not a penalty - it never reduces a rider's score.

Operator controls

• Settings > Safe Ride Check to enable, set window, set thresholds.
• Dashboard > Rider Score > Audit Log filtered by action='reaction_test_fail_lockout' to see who triggered a step-6 via reaction test.
• Rider profile > Reaction tests shows the last 30 days of attempts for any given rider (useful for appeal review).

ADA and accessibility note

Reaction tests can disadvantage riders with certain disabilities. If a rider self-discloses an accessibility constraint, the operator should configure an account-level exemption at Rider profile > Exemptions. The exemption skips the reaction test entirely for that rider. This is a v3.0 manual workflow; an in-app accessibility flag is on the v3.1 roadmap.

API surface

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