Jehle Dietrich von Kuenssberg, Connolly Sara, Godzala Michael, Cole Adam
Department of Emergency Medicine, State University of New York at Buffalo, Buffalo, New York 14215, USA.
J Trauma. 2010 Sep;69(3):708-14. doi: 10.1097/TA.0b013e3181ec6777.
The New York State (NYS) speed limit increased from 55 mph to 65 mph in August 1995. This study examines the change in motor vehicle fatality rates on the NYS thruway and NYS Interstates before and after the speed limit change. We also compare the fatality rates pre- and postincreased speed limit between the NYS thruway and other major NYS roadways, where speed limit remained unchanged at 55 mph.
The number of fatalities and vehicle miles traveled (VMT) on individual roadways were extracted from NYS Department of Transportation reports. The data were divided into groups by prespeed limit change, August 1992 to August 1995, and postspeed limit change, August 1995 to August 1998, and roads where the speed limit remained unchanged at 55 mph. Data were also analyzed to assess the effect of variability of speed and general topography on changes in fatality rates on roads where the speed limit was increased.
There was a 28.3% decrease in absolute mortality and a 42.6% decrease in mortality adjusted for VMT, on the NYS thruway after the speed limit increase from 55 mph to 65 mph. When compared with roadways, where the speed limit remained unchanged, there was a 52.4% reduction in fatality rates below the predicted rates after the speed limit increase (p = 0.009). On the NYS interstate system, there was a 13.5% decrease in absolute mortality and a 29.2% decrease in mortality adjusted for VMT, after the speed limit increase. The percentage of traffic traveling >10 mph faster than the speed limit dropped from 39% to 8% on roads, where the speed limit was increased from 55 mph to 65 mph. In the NYS interstate system, "flat" roads (elevation <200 m) had a 30.2% reduction in absolute mortality, whereas "mountainous" roads (elevations >200 m) had a 17.6% increase in absolute mortality in response to the speed limit increase (p < 0.001).
Motor vehicle speed is a key determinate of the severity of injury in an individual crash; however, speed variance and road topography have also been found to impact the total number of motor vehicle fatalities in the NY State highway system.
1995年8月，纽约州（NYS）的限速从每小时55英里提高到了每小时65英里。本研究调查了限速变化前后纽约州高速公路和州际公路上机动车死亡率的变化情况。我们还比较了纽约州高速公路限速提高前后与纽约州其他主要道路（限速保持在每小时55英里不变）的死亡率。
从纽约州运输部的报告中提取各条道路上的死亡人数和车辆行驶里程（VMT）。数据按限速变化前（1992年8月至1995年8月）、限速变化后（1995年8月至1998年8月）以及限速保持在每小时55英里不变的道路进行分组。还对数据进行了分析，以评估速度变化和总体地形对限速提高道路上死亡率变化的影响。
纽约州高速公路限速从每小时55英里提高到每小时65英里后，绝对死亡率下降了28.3%，经VMT调整后的死亡率下降了42.6%。与限速保持不变的道路相比，限速提高后死亡率比预测率低5️⃣2.4%（p = 0.009）。在纽约州州际公路系统中，限速提高后，绝对死亡率下降了13.5%，经VMT调整后的死亡率下降了29.2%。在限速从每小时55英里提高到每小时65英里的道路上，行驶速度比限速快10英里以上的交通流量百分比从39%降至8%。在纽约州州际公路系统中，“平坦”道路（海拔<200米）的绝对死亡率下降了30.2%，而“山区”道路（海拔>200米）的绝对死亡率因限速提高而上升了17.6%（p < 0.001）。
机动车速度是单次碰撞中受伤严重程度的关键决定因素；然而，速度差异和道路地形也被发现会影响纽约州公路系统中的机动车死亡总数。
