Tykes and bikes: injuries associated with bicycle-towed child trailers and bicycle-mounted child seats

Used in 2 entries

For each citing entry, the verbatim excerpt and Likelier's calculation notes (how the source's number was converted to the lifetime-probability framing) are shown below. Click through to read the full claim ledger.

1. [1] Child bike trailer Risk

   Statistic

   Estimated 322 trailer injuries (95% CI 158-486) over 9 years vs 2,015 mounted-seat injuries; 33% of trailer injuries involved motor vehicles; 83% of trailer cases had head/face injuries

   “"49 injuries to children during the 9-year study period [were identified]: 6 were associated with bicycle-towed trailers (estimated 322 injuries; 95% CI, 158-486) and 43 were related to bicycle-mounted child seats (estimated 2,015 injuries; 95% CI, 988-3,042). The mean age of injured children was 2.4 years and 51% were male. For trailers, motor vehicle collisions accounted for 33% of injuries and falls 50%; for mounted seats, 9% involved motor vehicles and 72% were falls. Head/face injuries: 83% (trailers) vs 49% (seats)."”

   Calculation notes

   Powell & Tanz observed 6 trailer cases in the NEISS sentinel hospitals, which extrapolated to 322 nationally over 9 years — about 36 per year. Against ~1.5M cumulative child-trailer-passenger-years, this is roughly 1 in 4,700 per passenger-year, or ~1 in 14,000 over a 3-year exposure. The 6x safety differential vs mounted seats (322 vs 2,015) is the headline finding. Wide CI is unavoidable with only 6 observed cases.
   

   Source date: 2000-04-01 · Accessed: 2026-05-31

2. [2] Child rear bike seat Risk

   Statistic

   Estimated 2,015 injuries (95% CI 988-3,042) over 9 years to children riding in US bicycle-mounted child seats; 9% involved motor vehicles, 72% were falls; 49% had head/face injuries

   “"49 injuries to children during the 9-year study period [were identified]: 6 were associated with bicycle-towed trailers (estimated 322 injuries; 95% CI, 158-486) and 43 were related to bicycle-mounted child seats (estimated 2,015 injuries; 95% CI, 988-3,042). The mean age of injured children was 2.4 years and 51% were male. For trailers, motor vehicle collisions accounted for 33% of injuries and falls 50%; for mounted seats, 9% involved motor vehicles and 72% were falls. Head/face injuries: 83% (trailers) vs 49% (seats)."”

   Calculation notes

   Powell & Tanz analyzed NEISS data for 1990-1998 (9 years). The 2,015 figure is the extrapolated US national estimate from observed cases. We use 2,015 / ~1.5M cumulative child-passenger-years (9 years x ~166k US children riding as passengers/year, estimated from cycling participation surveys) for ~0.13% over the 9-year window, or roughly 1 in 750 per child-passenger-year. Over a typical 3-year exposure window, ~1 in 2,500 for ER-treated injury. The denominator is the dominant uncertainty.
   

   Source date: 2000-04-01 · Accessed: 2026-05-31

Also cited in these entries

Transport

Child bike trailer

What are the odds of serious injury to a child riding in a towed bicycle trailer?

1 in 14,286 lifetime(0.007%)activityoverrated

Transport

Child rear bike seat

What are the odds of serious injury to a child riding in a rear-mounted bike seat?

1 in 2,500 lifetime(0.04%)activityoverrated