Traffic Safety Facts

Traffic Tech – Technology Transfer Series

Number 360 February 2009

U.S. Department of Transportation 1200 New Jersey Avenue SE., Washington, DC 20590

National Highway Traffic Safety Administration

This	 document	 explores	 how	 emerging	 digital	 and	

communications	technology	can	advance	safety	on	the	

Nation’s	highways.	The	range	of	technology	described	

in	this	report	is	available	or	will	be	available	in	the	near	

future	to	improve	traffic	safety.		As	new	traffic	safety	

applications	become	widespread	and	implementation	

costs	decrease,	there	could	be	a	network	of	advanced	

systems	that	improve	traffic	safety	by	providing	information	and	services	to	drivers,	traffic	operations	agencies,	emergency	management	services	personnel,	and	

law	enforcement	professionals.

Technologies

Electronic communications is the key to traffic safety 

technologies. Types of communications systems and 

example applications include: 

■ Vehicle to driver, in which the vehicle communicates information to drivers when predetermined 

criteria are met, such as if a vehicle drifts out of its 

lane.

■ Vehicle to vehicle, which enables communication 

among vehicles for such applications as crash avoidance technologies and allowing law enforcement 

officials to acquire identification information about 

a particular vehicle. 

■ Vehicle to and from roadside, in which roadside 

communications devices send and receive message 

to and from passing vehicles. The most common 

application of this technology is electronic toll collection, but there are many potential traffic safety 

applications.

■ Vehicle to and from traffic and emergency management centers, including such applications as 

automatic crash notification that notifies an emergency management center when a vehicle has been 

involved in a crash.

Technology Applications for Traffic Safety 

Programs: A Primer

Haddon Matrix

The Haddon Matrix is a useful construct to assess the 

various stages of a crash (before, during, and after) 

and factors that contribute to crashes (human, vehicular, and environmental). Table 1 incorporates the technologies into the Haddon Matrix.

This report applies the Haddon Matrix to each of the 

“Four E’s” of traffic safety:

■ Engineering - Examples include anti-lock brake 

systems that prevent skidding and electronic stability traction control that helps avoid vehicle rollovers. Engineering interventions generally occur in 

the pre- and during- crash phases of the Haddon 

Matrix. 

■ Emergency response – Examples include automated 

crash notification systems that notify emergency 

management centers that a vehicle has been in a 

crash and improved 911 services that can detect the 

location of cell phone callers (enhanced 911) and that 

can handle non-voice communication such as video 

and data streams (next-generation 911). Emergency 

response technologies apply to the post-crash time 

period.

■ Enforcement and regulations – Examples include 

electronic vehicle tags that allow law enforcement 

personnel to identify specific vehicles and cameras 

that detect and identify vehicles that run red lights. 

Enforcement and regulatory activities occur primarily before a crash. 

■ Education and information – Examples include 

various driver information applications that inform 

the driver about road and traffic conditions. Education and information activities affect primarily percrash conditions.
Challenges 

As	with	all	new	technology	applications,	traffic	safety	

technologies	come	with	a	variety	of	design	challenges	

that	 must	 be	 met	 prior	 to	 full	 implementation.	 	 The	

human-machine	 interface	 (HMI)	 is	 perhaps	 the	 most	

important	consideration	in	traffic	safety	technologies.	

The	 primary	 requirement	 of	 the	 in-vehicle	 HMI	 is	 to	

deliver	needed	or	desired	information	while	minimizing	driver	distraction.		This	can	be	done	through	careful	

placement	of	the	HMI	device	within	the	vehicle	and	by	

the	way	it	relays	relevant	information.		Available	technologies	for	HMI	include	voice	activation,	speech	recognition,	dashboard	lights	and	icons,	heads-up	or	panel	

displays,	audio	devices,	voice	synthesizers,	haptic	systems,	and	onboard	printers.	Other	challenges	include	

the	need	to	protect	the	security	and	privacy	of	data,	the	

need	for	the	various	technologies	to	be	interoperable,	

and	 the	 need	 to	 ensure	 that	 the	 data	 generated	 and	

communicated	by	these	new	technologies	are	accurate	

and	 reliable.	 There	 are	 other	 challenges	 that	 are	 less	

technical	 in	 nature,	 such	 as	 encouraging	 widespread	

deployment	 and	 managing	 interorganizational	 issues	

related	to	new	technology	applications.		

If	you	have	questions	about	Technology Applications 

for Traffic Safety Programs: A Primer please	write	to	

the	Office	of	Behavioral	Safety	Research,	NHTSA,	NTI130,	 1200	 New	 Jersey	 Avenue	 SE.,	 Washington,	 DC	

20590,	fax	202-366-7394.	Ian	Reagan	was	the	Contracting	Officer’s	Technical	Representative	for	this	project.	

Table 1. Fitting New and Emerging Technologies Within the Haddon Matrix.

Technology Phase Human Vehicle Environment

Rear-end crash avoidance ×

Merge × ×

Road departure × ×

Lane change × ×

Intersection crash avoidance × ×

Drowsy driver

Pre-Crash

×

Night vision × ×

Variable speed limits × × ×

Electronic stability program ×

Roll stability control ×

Electronic brake systems ×

Steer-by-wire ×

More protective belt designs

During Crash

×

Automatic vehicle safety-feature adjustments ×

Side air bags ×

External air bags ×

Materials to reduce pedestrian injury ×

Automated crash notification 

Post-Crash

× ×

Passenger medical information × ×

Standardized information exchange × ×

Electronically collected crash data × ×

Consolidation of crash & medical data ×

E911 ×

NG911 × ×

EMS Technology Evaluation Template ×

TRAFFIC TECH	is	a	publication	to	disseminate	information	about	

traffic	 safety	 programs,	 including	 evaluations,	 innovative	 programs,	and	new	publications.	Feel	free	to	copy	it	as	you	wish.	If	

you	would	like	to	receive	a	copy,	contact	Dr.	Angela	Eichelberger,	

Editor,	fax	202-366-7394,	e-mail:	traffic.tech@dot.gov. 1200	New	Jersey	Avenue	SE.,	NTI-130

Washington,	DC	20590