Driver Safety Score

The five behavior inputs (hard braking, hard acceleration, speeding, phone use, seatbelt violations) are entered as rates -- events per 1,000 miles -- rather than raw counts, so the scoring math already has everything it needs without knowing the total distance driven. Evaluation Period Miles is used only to compute the separate Events Per Mile figure; it plays no role in the Safety Score, Rating, or Risk Category calculations.

Each behavior category's contribution to the score deduction is capped -- hard braking can subtract at most 20 points regardless of how far above that threshold the event rate climbs. That's a deliberate design choice so one especially bad category doesn't single-handedly drive the score to zero; once a category's cap is reached, further increases in that one metric alone stop moving the score, though other categories (accidents, moving violations) still have no cap and continue to subtract. The separately displayed Braking and Speeding Sub-Scores don't share this cap -- they use their own independent 0-100 scales (100 minus a per-event penalty, floored at 0) that are more sensitive than each behavior's capped contribution to the blended Safety Score, so treat them as a category-specific view of that one behavior in isolation, not as a breakdown that sums back up to the Safety Score.

Unlike the five behavior-rate categories, at-fault Accidents and Moving Violations are entered as raw incident counts for the evaluation period and are deducted at a flat rate per incident (15 points per accident, 10 per violation) with no maximum -- reflecting that these are already-realized, documented safety outcomes rather than precursor behaviors, so this calculator treats them as more serious and doesn't cap how much they can pull the score down.

This calculator ranks the five behavior categories by how many points each one is currently subtracting from the score (before any cap is applied) and reports whichever category has the largest deduction as the Top Improvement Area -- the single behavior change that would recover the most points. If every category is currently contributing zero deduction, it reports "None needed" instead.

Insurance Impact is a banded estimate of the discount or surcharge a telematics-based insurance program might apply based on Safety Score: a -10% discount at a score of 90 or above, -5% at 80-89, no adjustment at 70-79, a +10% surcharge at 60-69, and +15% below 60. It's a rough illustration of how usage-based insurance programs typically tier pricing by safety score, not a quote from any specific insurer -- actual programs vary in their bands and criteria.