< Return to Mandatory bicycle helmet laws in the United States or to the home page

Injury data suggests fewer cyclists and an increased proportion of head injuries

In November 2019, the National Transportation Safety Board in the United States recommended that "all 50 states, the District of Columbia and Puerto Rico, require that all persons wear a helmet while riding a bicycle" - i.e. that all-age mandatory bicycle helmet laws be enforced in all US jurisdictions.

This page collates and interprets US Government data available to the NTSB on cyclist all-body injuries and head injuries among different age brackets since 1999, at which time many states were enforcing child bicycle helmet laws and an increasing number of adults were voluntarily wearing bike helmets.

That injury data suggests the major influence of mandatory child helmets and increased adult wearing has been to reduce cycling participation among children and teenagers, along with an increased proportion of head injuries and concussion suffered among all age brackets.

United States cyclist injury data up to 2017 from Centers for Disease Control and Prevention suggests an increase from 2001 to 2011 but significant annual decreases in cyclist injuries since then:

2001 - 519,424
2010 - 516,912
2011 - 536,844
2012 - 532,546
2013 - 494,430
2014 - 481,328
2015 - 467,800
2016 - 405,095
2017 - 329,831

All US states have voluntary bicycle helmet wearing for adults, and about half the states have child/teenage helmet laws. Because of this myriad jurisdictional enactment of mandatory helmet laws and regulations, it's not known how much of the following demographic total injury data is due to helmets preventing injuries among youth (and adults to a lesser degree), and how much is a reflection of cycling participation in the different age groups.

0-4yo
2001 - 29,594
2017 - 11,438

5-9yo
2001 - 110,678
2017 - 39,388

10-14yo
2001 - 144,221
2017 - 49,295

15-19yo
2001 - 56,514
2017 - 31,679

20-24yo
2001 - 32,384
2017 - 26,061

25-29yo
2001 - 24,022
2017 - 21,063

30-34yo
2001 - 23,174
2017 - 20,879

35-39yo
2001 - 24,702
2017 - 17,713

40-44yo
2001 - 20,879
2017 - 15,602

45-49yo
2001 - 17,927
2017 - 15,691

50-54yo
2001 - 13,162
2017 - 23,329

55-59yo
2001 - 7,787
2017 - 19,772

60-64yo
2001 - 4,848
2017 - 13,394

65-69yo
2001 - 3,988
2017 - 10,444

Alternatively, the total all-body injury data can be considered on an annual basis in age brackets with corresponding populations (in brackets):

0-15yo

2001 - 304,094 (64,534,135)
2002 - 305,370 (64,660,906)
2003 - 303,627 (64,801,304)
2004 - 287,733 (64,916,665)
2005 - 270,203 (64,976,015)
2006 - 243,927 (64,923,224)
2007 - 253,285 (65,046,110)
2008 - 233,609 (65,226,366)
2009 - 248,411 (65,347,488)
2010 - 238,906 (65,470,033)
2011 - 243,316 (65,328,388)
2012 - 223,735 (65,258,081)
2013 - 196,353 (65,218,469)
2014 - 188,520 (65,219,922)
2015 - 158,230 (65,251,659)
2016 - 132,228 (65,177,894)
2017 - 108,281 (65,136,112)

16-30yo

2001 - 98,045 (59,167,299)
2002 - 87,215 (59,441,763)
2003 - 83,101 (59,801,321)
2004 - 88,306 (60,528,244)
2005 - 87,063 (61,390,491)
2006 - 92,153 (62,326,391)
2007 - 105,175 (63,218,545)
2008 - 109,900 (63,945,369)
2009 - 116,455 (64,499,386)
2010 - 114,556 (64,771,039)
2011 - 127,979 (65,176,293)
2012 - 128,569 (65,500,410)
2013 - 120,706 (65,736,469)
2014 - 114,380 (65,997,959)
2015 - 118,575 (66,370,380)
2016 - 99,428 (66,668,591)
2017 - 74,722 (66,916,826)

31-45yo

2001 - 67,898 (65,787,622)
2002 - 65,324 (65,766,170)
2003 - 59,777 (65,312,851)
2004 - 59,906 (64,708,402)
2005 - 64,333 (64,029,628)
2006 - 65,911 (63,323,464)
2007 - 64,000 (62,592,260)
2008 - 69,081 (62,026,351)
2009 - 68,911 (61,538,057)
2010 - 69,634 (61,255,905)
2011 - 68,229 (61,122,595)
2012 - 70,366 (61,271,193)
2013 - 72,124 (61,561,089)
2014 - 68,404 (61,902,232)
2015 - 64,184 (62,146,144)
2016 - 60,816 (62,314,406)
2017 - 54,222 (62,528,530)

46-60yo

2001 - 36,244 (51,433,588)
2002 - 32,770 (53,214,617)
2003 - 32,672 (54,983,948)
2004 - 39,307 (56,489,599)
2005 - 43,252 (58,095,999)
2006 - 46,602 (59,866,565)
2007 - 54,982 (61,534,373)
2008 - 60,952 (62,252,309)
2009 - 63,409 (63,127,728)
2010 - 69,081 (63,783,784)
2011 - 69,736 (64,501,481)
2012 - 82,436 (64,731,628)
2013 - 77,349 (64,785,609)
2014 - 71,191 (64,717,383)
2015 - 75,112 (64,619,913)
2016 - 69,706 (64,606,678)
2017 - 57,383 (64,541,250)

61-75yo

2001 - 11,142 (28,751,091)
2002 - 10,846 (29,028,877)
2003 - 10,814 (29,463,203)
2004 - 12,715 (30,207,723)
2005 - 12,830 (30,886,128)
2006 - 14,498 (31,552,694)
2007 - 14,422 (32,266,032)
2008 - 16,606 (33,912,656)
2009 - 18,789 (35,382,095)
2010 - 19,325 (36,530,299)
2011 - 23,139 (38,283,123)
2012 - 22,679 (39,738,170)
2013 - 23,258 (41,218,256)
2014 - 33,187 (42,726,944)
2015 - * (44,294,386)
2016 - 34,698 (45,913,841)
2017 - 29,068 (47,460,463)

The data clearly show that children and teenagers are responsible for the overall cyclist injury reduction in the US. The annual data suggest the youth injury decline started around the year 2011.

Listed above, the 0-15yo injury reduction from 243,316 in 2011 to 108,281 in 2017 is a 55.5% drop in total body injuries, which helmets cannot achieve even if they prevent all head injuries.

Child helmet laws were introduced in different US jurisdictions from 1987, with enforcement in the new millennium in the District of Columbia (2000 to 2004), Hawaii (2001), Louisiana (2002), New Hampshire (2006), New Mexico (2007) and North Carolina (2001). Numerous local jurisdictions have also introduced child helmet laws since the year 2000.

Declining participation is likely the main reason for the injury decline (although there are other possible variables such as reduced traffic speeds or drink driving enforcement across the US). In the data above, baby boomers and pensioners are propping up the injury/participation trends.

Motor vehicle occupant injury rates have been declining per capita and it can be argued road traffic is becoming safer (or possibly safer vehicles, air bags, etc.):

2001 - 3,052,560 (284,968,955)
2002 - 2,998,661 (287,625,193)
2003 - 3,033,466 (290,107,933)
2004 - 3,008,202 (292,805,298)
2005 - 2,864,022 (295,516,599)
2006 - 2,730,648 (298,379,912)
2007 - 2,661,379 (301,231,207)
2008 - 2,587,242 (304,093,966)
2009 - 2,650,299 (306,771,529)
2010 - 2,771,497 (308,745,538)
2011 - 2,691,162 (311,644,280)
2012 - 2,569,565 (313,993,272)
2013 - 2,467,032 (316,234,505)
2014 - 2,417,432 (318,622,525)
2015 - 2,632,009 (321,039,839)
2016 - 2,730,403 (323,405,935)
2017 - 2,507,560 (325,719,178)

However, pedestrian injury rates haven’t been improving numerically or per capita, so it can be argued there has been no decrease in accident/injury risk for people not in cars:

2001 - 176,189 (284,968,955)
2002 - 174,235 (287,625,193)
2003 - 175,949 (290,107,933)
2004 - 175,136 (292,805,298)
2005 - 171,721 (295,516,599)
2006 - 170,048 (298,379,912)
2007 - 172,234 (301,231,207)
2008 - 196,991 (304,093,966)
2009 - 189,060 (306,771,529)
2010 - 215,188 (308,745,538)
2011 - 222,030 (311,644,280)
2012 - 219,194 (313,993,272)
2013 - 207,385 (316,234,505)
2014 - 196,140 (318,622,525)
2015 - 187,344 (321,039,839)
2016 - 193,366 (323,405,935)
2017 - 193,866 (325,719,178)

The National Electronic Injury Surveillance System maintained by the US Consumer Product Safety Commission also provides cyclist hospital attendance injury data from 1999 to 2018, with similar trends to the CDC data above:

All cyclist injuries

1999 - 594,092
2009 - 534,359
2010 - 530,520
2011 - 539,847
2012 - 547,265
2013 - 521,185
2014 - 501,495
2015 - 487,788
2016 - 459,741
2017 - 446,969
2018 - 415,174

It might be argued in the NEISS dataset that the injury/participation decline started in 2012. The NEISS also provides injury demographics and below is a comparison of just 1999 and 2018:

1999 cyclists all injuries

0 to 9 years - 197,173
10 to 19 years - 230,806
20 to 29 years - 50,562
30 to 39 years - 47,078
40 to 49 years - 34,320
50 to 59 years - 15,941
60 to 69 years - *
70 to 79 years - *

2018 cyclists all injuries

0 to 9 years - 66,904
10 to 19 years - 94,365
20 to 29 years - 53,653
30 to 39 years - 45,566
40 to 49 years - 39,278
50 to 59 years - 53,661
60 to 69 years - 38,580
70 to 79 years - 18,184

* Less than 1,200 does not register

The NEISS also allows a breakdown of injury types. Below are head injuries among decadal demographics (two years rather than one year to provide a more comprehensive comparison) as estimated for 1999-2000, 2011-2012 and 2017-2018:

1999+2000 cyclist head injuries

0 to 9 years - 58,632
10 to 19 years - 49,879
20 to 29 years - *
30 to 39 years - 9,977
40 to 49 years - 7,371
50 to 59 years - 3,962
60 to 69 years - 1,294
70 to 79 years - *

2011+2012 cyclist head injuries

0 to 9 years - 37,690
10 to 19 years - 45,961
20 to 29 years - 21,396
30 to 39 years - 13,000
40 to 49 years - 14,270
50 to 59 years - 17,676
60 to 69 years - 8,613
70 to 79 years - 2,722

2017+2018 cyclist head injuries

0 to 9 years - 23,145
10 to 19 years - 29,202
20 to 29 years - 16,485
30 to 39 years - 13,521
40 to 49 years - 10,020
50 to 59 years - 18,402
60 to 69 years - 12,168
70 to 79 years - 5,679

youth cyclist head injuries in us

adult cyclist head injuries in us

Concussion totals can also be estimated:

1999+2000 cyclist concussions

0 to 9 years - 7,308
10 to 19 years - 11,176
20 to 29 years - 1,464
30 to 39 years - 1,546
40 to 49 years - *
50 to 59 years - *
60 to 69 years - *
70 to 79 years - *

2011+2012 cyclist concussions

0 to 9 years - 5,756
10 to 19 years - 11,372
20 to 29 years - 4,155
30 to 39 years - 2,584
40 to 49 years - 2,926
50 to 59 years - 2,523
60 to 69 years - 1,374
70 to 79 years - *

2017+2018 cyclist concussions

0 to 9 years - 3,532
10 to 19 years - 8,153
20 to 29 years - 3,553
30 to 39 years - 2,699
40 to 49 years - 1,478
50 to 59 years - 2,372
60 to 69 years - 1,536
70 to 79 years - *

youth cyclist concussions in us

adult cyclist concussions in us

0-19yo cyclists had 427,979 total injuries in 1999 and 161,269 in 2018. That’s a 62.3% reduction.

However, 0-19yo head injuries were 52,993 in 1999 and 25,223 in 2018. That’s a 52.4% reduction.

0-19yo concussions were 8,301 in 1999 and 5,693 in 2018. That’s a 31.4% reduction.

The 27,770 reduction in head injuries is well short of the 266,710 reduction in total injuries from 1999 to 2018, adding to the evidence that reduced child and teenage total body and head injury rates since 1999 in the US have been due to reduced cycling participation, not helmets.

Head injuries were 12.4% of total 0-19yo injuries in 1999 (52,993 / 427,979) and concussions were 1.9% (8,301 / 427,979).

However, head injuries were 15.6% of total 0-19yo injuries in 2018 (25,223 / 161,269) and concussions were 3.5% (5,693 / 161,269).

Conclusion

The publicly-available government data provides strong evidence that the main influence of child bicycle helmet laws in half the American states, as well as voluntary adult helmet wearing, has been to reduce cycling participation among children and teenagers and to increase the proportion of head injuries/concussion in cycling communities where helmet wearing has increased.

The severity of head injuries with or without helmets has not been considered in this analysis, but a reduction in regular recreation exercise (cycling) has a profound impact on public health, particularly within the formative years of youth, and the increased proportions of head injury raise questions about the efficacy of any reduced head injury severity.

If the NTSB recommendation for national all-age mandatory bicycle helmets in the United States was to be adopted, the likely consequence would be similar to that experienced in Australia and New Zealand where cycling participation has plunged and there has been a negligible positive influence on cyclist head injuries.

Close



Back To Top