Methodology and sources
Data files
| Figure | Source | Checked |
|---|---|---|
| Registered motorcycles by state, 2023 | FHWA Highway Statistics 2023, Table MV-1 (motorcycle registrations) | 2026-10-23 |
| Motorcyclists killed and % helmeted (known use), 2023 | NHTSA Traffic Safety Facts 2023 Data: Motorcycles (DOT HS 813 732), Table 7 | 2026-10-23 |
| Current helmet law | IIHS motorcycle helmet law table (current as of October 2026) | 2026-10-23 |
| Helmet effectiveness (37%) | NHTSA, Motorcycle Helmet Effectiveness Revisited, DOT HS 809 715 | 2026-10-23 |
| Coverage lines and vehicle checklists | Written from standard RV and motorcycle policy forms; descriptive, not policy wording | 2026-10-23 |
Checks on the data
The 51 state registration figures sum exactly to FHWA's US total of 9,516,910, and the 51 death counts to NHTSA's 6,335. The site's tests fail if either total drifts.
Formulas
- Deaths per 10,000 registered motorcycles = state deaths ÷ state registrations × 10,000, rounded to one decimal. This is derived here; NHTSA publishes the national figure per 100,000 (66.57), which is 6.7 per 10,000.
- Tier: high = above the third quartile of state rates, low = below the first quartile, otherwise mid.
- Helmet use by law type: each state's helmeted share weighted by its deaths, grouped by the state's current IIHS law.
- Nearest states: the states with the closest rates.
How the checklist works
Each vehicle type has a default list of coverage lines, set from what a policy for that vehicle normally includes or offers. Four answers then change the list. A financed vehicle adds collision and comprehensive, because lenders require both. Living in an RV full time adds full-timer coverage, and full-timer coverage is removed when the box is not ticked, because it is designed for people with no other home. Storing a vehicle for part of the year adds a lay-up option, and custom parts add scheduled equipment cover. The checklist never says how much any line costs or what limit to buy; those depend on the insurer, the state and what you own.
Known limits
Death rate per 10,000 registered motorcycles is derived here: deaths ÷ FHWA registrations × 10,000. NHTSA's national figure is per 100,000; per 10,000 is used because it reads better state by state.
Registration counts differ in meaning across states (permanent or multi-year plates inflate them), so the derived rate is a comparison aid, not a crash risk for any rider.
Deaths per registered bike reflects riding season and how long bikes stay registered, as well as risk. The site does not compare death rates by helmet law as evidence about helmets; see the helmet law page.
Left out, and why
- State minimum auto/motorcycle liability limits: no primary compiled source reachable; several states changed limits in 2025. Phase 2 via each state's statute.
- Premiums: none published; rates are filed per state and insurer.