Table 3.
Crash and environmental characteristics of bicycle-motor vehicle crashes in Iowa, 2001-2011
| Bicyclist Location | |||||||
|---|---|---|---|---|---|---|---|
| Total (N=4437) | Intersection (N=2538) | Non-intersection (N=1899) | |||||
| Characteristic | N | % | N | % | N | % | p-value |
| Crash Characteristics | |||||||
| Motor vehicle type | 0.10 | ||||||
| Passenger car | 2631 | 59.3 | 1518 | 59.8 | 1113 | 58.6 | |
| Pick-up truck | 676 | 15.2 | 377 | 14.9 | 299 | 15.7 | |
| Van or mini-van | 406 | 9.2 | 229 | 9.0 | 177 | 9.3 | |
| SUV | 500 | 11.3 | 302 | 11.9 | 198 | 10.4 | |
| Other/Unknown | 224 | 5.1 | 112 | 4.4 | 112 | 5.9 | |
| Motor vehicle action | <0.01 | ||||||
| Moving essentially straight | 2563 | 57.8 | 1300 | 51.2 | 1263 | 66.5 | |
| Turning (L, R, or U-turn) | 1358 | 30.6 | 1025 | 40.4 | 333 | 17.5 | |
| Other/Unknown | 516 | 11.6 | 213 | 8.4 | 303 | 16.0 | |
| Day | 0.19 | ||||||
| Weekend | 908 | 20.5 | 502 | 19.8 | 406 | 21.4 | |
| Weekday | 3529 | 79.5 | 2036 | 80.2 | 1493 | 78.6 | |
| Time of day a | 0.30 | ||||||
| 10:00pm to 5:59 am | 229 | 5.2 | 123 | 4.9 | 106 | 5.6 | |
| 6:00 am to 9:59 am | 499 | 11.3 | 302 | 11.9 | 197 | 10.4 | |
| 10:00 am to 2:59 pm | 1106 | 25.0 | 637 | 25.1 | 469 | 24.8 | |
| 3:00 pm to 9:59 pm | 2596 | 58.6 | 1474 | 58.1 | 1122 | 59.2 | |
| Season | 0.39 | ||||||
| Winter (Dec-Feb) | 214 | 4.8 | 126 | 5.0 | 88 | 4.6 | |
| Spring (Mar-May) | 1022 | 23.0 | 588 | 23.2 | 434 | 22.9 | |
| Summer (Jun-Aug) | 1978 | 44.6 | 1105 | 43.5 | 873 | 46.0 | |
| Fall (Sep-Nov) | 1223 | 27.6 | 719 | 28.3 | 504 | 26.5 | |
| Location | <0.01 | ||||||
| Rural (outside city limits) | 228 | 5.1 | 41 | 1.6 | 187 | 9.9 | |
| Urban (within city limits) | 4132 | 93.1 | 2468 | 97.2 | 1664 | 87.6 | |
| Unknown | 77 | 1.7 | 29 | 1.1 | 48 | 2.5 | |
| Contributing circumstances, bicyclist | <0.01 | ||||||
| Improper crossing | 624 | 14.1 | 317 | 12.5 | 307 | 16.2 | |
| Darting | 267 | 6.0 | 108 | 4.3 | 159 | 8.4 | |
| Failure to yield right of way | 365 | 8.2 | 213 | 8.4 | 152 | 8.0 | |
| Failure to obey traffic signs/signals/officer | 444 | 10.0 | 367 | 14.5 | 77 | 4.1 | |
| Wrong side of road | 117 | 2.6 | 52 | 2.1 | 65 | 3.4 | |
| None reported | 419 | 9.4 | 247 | 9.7 | 172 | 9.1 | |
| Other/Unknown | 2201 | 49.6 | 1234 | 48.6 | 967 | 50.9 | |
| Contributing circumstances, motorist | <0.01 | ||||||
| Failure to yield right of way | 1067 | 24.1 | 730 | 28.8 | 337 | 17.8 | |
| Swerving/evasive action | 195 | 4.4 | 89 | 3.5 | 106 | 5.6 | |
| Vision obstructed | 141 | 3.2 | 53 | 2.1 | 88 | 4.6 | |
| No improper action | 1871 | 42.2 | 1053 | 41.5 | 818 | 43.1 | |
| Other/Unknown | 1163 | 26.2 | 613 | 24.2 | 550 | 29.0 | |
| Major cause | <0.01 | ||||||
| Both Motor Vehicle and Bicycle | 266 | 6.0 | 157 | 6.2 | 109 | 5.7 | |
| Motor vehicle | 1137 | 25.6 | 715 | 28.2 | 422 | 22.2 | |
| Bicycle | 1551 | 35.0 | 900 | 35.5 | 651 | 34.3 | |
| Neither | 1483 | 33.4 | 766 | 30.2 | 717 | 37.8 | |
| Environmental Characteristics | |||||||
| Posted Speed Limit (mph) | <0.01 | ||||||
| 25 & Under | 2622 | 59.1 | 1520 | 59.9 | 1102 | 58.0 | |
| 30-35 | 1276 | 28.8 | 814 | 32.1 | 462 | 24.3 | |
| 40-50 | 140 | 3.2 | 74 | 2.9 | 66 | 3.5 | |
| 55+ | 399 | 9.0 | 130 | 5.1 | 269 | 14.2 | |
| Vision obscurement | <0.01 | ||||||
| No | 3270 | 73.7 | 1942 | 76.5 | 1328 | 69.9 | |
| Yes | 510 | 11.5 | 234 | 9.2 | 276 | 14.5 | |
| Unknown | 657 | 14.8 | 362 | 14.3 | 295 | 15.5 | |
| Surface conditions | 0.56 | ||||||
| Dry | 4034 | 90.9 | 2315 | 91.2 | 1719 | 90.5 | |
| Wet | 263 | 5.9 | 149 | 5.9 | 114 | 6.0 | |
| Other/Unknown | 140 | 3.2 | 74 | 2.9 | 66 | 3.5 | |
| Reduced Lighting a | <0.01 | ||||||
| No (daylight or lighted roadway) | 4046 | 91.9 | 2375 | 94.4 | 1671 | 88.5 | |
| Yes (dusk, dawn, unlighted roadway) | 333 | 7.6 | 128 | 5.1 | 205 | 10.9 | |
| Unknown | 26 | 0.6 | 13 | 0.5 | 13 | 0.7 | |
mph = miles per hour
a
Numbers do not sum to total because of missing data.