Road safety Transportation safety in the United States

1 road safety

1.1 fatality rates state
1.2 pedestrians , cyclists
1.3 rates per driver s license
1.4 risk factors
1.5 cause
1.6 vmt

road safety

car accidents common in united states , majority of these road crashes caused human error.

the target united states reduce fatalities rate @ 1.02 fatalities per 100 million vehicles miles traveled in 2014.

fatality rates state

the death rate per 100 million miles traveled in 2015 ranged 0.52 in massachusetts 1.89 in south carolina. (the massachusetts rate translates 3.25 fatalities per 1 billion vehicle-km. south carolina rate translates 11.8 fatalities per 1 billion vehicle-km.) in south carolina, north dakota , texas, more 40% of road fatalities attributed driving under influence (dui). plot of vehicle-miles traveled per capita vs fatalities per 100,000 population shows montana, south carolina , west virginia outliers higher expected fatalities.

enforcement , compliance seat belt laws varies state. (massachusetts, had lowest death rate per 100 million miles traveled in 2015, among states lowest use of seat belts.) states require motorcycle helmets while others not. speed limits, traffic density, topography, climate , many other factors affect divergent accident rates state. speed limits in texas, utah, , rhode island prima facie rather absolute. allows motorists in states defend against speeding charge if can proven speed reasonable , prudent. in driving conditions, many drivers in prima facie states presume (usually correctly) police allow tolerance in enforcement. in states absolute speed limits, enforcement , penalties vary 1 state another. these , other reasons, state-to-state comparisons difficult. there many studies examining increases in interstate speed limits 55 mph 65, 70 , 75 mph. found fatality rates increased on interstate highways speed limits raised. 1 study examined change 55 65 mph found higher interstate speed limits improved overall highway safety drawing traffic less safe secondary highways safer interstate highways. since changes 80 mph speed limits in states (and 85 mph on 1 section of toll highway in texas) relatively recent, robust analysis not yet available. anecdotal evidence suggests actual vehicle speeds did not increase as speed limits did. also, police may enforcing new higher limits more strictly enforced prior limits. in states, police have reallocated resources focus more on impaired , distracted driving. higher speed limits predominantly in rural states, tend republican states. many republican voters, speed limits (and seat belt laws) seen intrusions on personal liberty. according transportation historian owen gutfreund, state governments may raise speed limits because raising speed limit “sounds such easy regulatory win.” it’s simple way “get government out of face.”

pedestrians , cyclists

dedicated cycling facility in new york city

as cars have become safer occupants (due airbags, structural crashworthiness , other improvements) percent of pedestrian fatalities percent of total motor vehicle fatalities steadily increased 11% in 2004 15% in 2014 according nhtsa data. bicyclists accounted 2 percent of traffic deaths in 2014.

rates per driver s license

one can calculate auto fatalities per driver s license. 1990 2009, number has been improving: 1 death per 3,745 driver s licenses in 1990 1 per 6,200 driver s licenses in 2009. crowded, traffic-choked northeastern cities including washington, d.c., baltimore, boston, providence, philadelphia, newark, hartford, new haven, springfield , worcester, massachusetts, have car accidents. national highway traffic safety administration through fatality analysis reporting system stated auto fatalities continue leading cause of death young adults.

risk factors

moose (a. a. gigas) crossing road in alaska

rural non-interstate highways particularly risky. two-lane non-divided highways built lower standards interstate highways. drivers drunk , not wearing seat belts. speeding common. deer, elk , moose crossing highway add risk compared urban highways. in event of accident in remote area, injured victims may not receive emergency medical care in time save lives.

many accidents when driving personal vehicles caused distracted driving. according american automobile association (aaa), distraction plays factor in 60% of moderate serious teen car crashes. specifically, passenger , cell phone interaction accounted 27% of crashes, leading cause. drivers looking away target (roadway) accounted 19%.

non-use of seat belts significant risk factor. according col. tom butler, chief of montana highway patrol, preliminary 2015 data indicated 178 of 224 vehicle occupant fatalities of individuals not wearing seat belts. fine in montana not wearing seat belt in 2015 $20. although speed limits increased 75 mph 80 mph on rural interstates year, biggest statewide increase in both crashes , deaths occurred on secondary roads. forty-three people died on montana two-lane roads outside of towns neither u.s. or state highways.

average trip duration may greater in rural states, may mean driver fatigue more salient risk factor in rural states in more densely populated states. data on number of hours driven in day , accident rates commercial drivers required keep driving logs. (see next section.)

human factor 1 of more significant in various factors leading fatalities.

according fdot:

«when speeding compared fault, drivers traveling @ speed on 4 mph on posted limit highly overrepresented in fault. amount of speeding increases, degree of overrepresentation increases; however, @ 5-9 miles on limit, drivers overrepresented in fault factor of on 2.0. ».
«drinking drivers between 3.5 , 18 times @ fault in crash, depending on amount of alcohol ingested.  »


cause

several causes involved:

distracted driving
drunk driving
speeding
reckless driving
rain
running red lights (traffic light)
night driving
design defects
tailgating
wrong-way driving or improper turns
teenage drivers
drugs
potholes
tire blowouts
animal crossings (deer–vehicle collisions)
construction sites

























































vmt

it understood fatalities increase increase of vmt, not systematic fatalities might remain quite stable while vmt change.