Number 321 February 2007

Nighttime Seat Belt Use is Lower Than Daytime in 

New Mexico

U.S. Department of Transportation 400 Seventh Street, SW, Washington, DC 20590

National Highway Traffic Safety Administration

In June 2005, Preusser Research Group, under 

contract from the National Highway Traffic Safety 

Administration, conducted a nighttime seat belt use 

survey in New Mexico. Previous studies found lower 

nighttime seat belt use rates in Connecticut, New York 

and Pennsylvania. This study sought to confirm those 

findings, using military-grade night-vision technology 

to collect nighttime belt use data, measuring day and 

night belt use in both densely and sparsely populated 

locations throughout New Mexico.

Method

Each June, the New Mexico Department of Health 

typically conducts a statewide survey of seat belt 

use based on a random proportional selection of 

observational survey sites on roadways that represent 

the State’s population demographics and roadway 

travel. The present nighttime study used the New 

Mexico Statewide Survey of Safety Belt Use as a 

template. During the first two weeks of June 2005, 

observations were made at 108 sites, once during 

the day between 7 a.m.-7 p.m., and again at night 

between 9 p.m. and 3:59 a.m. (similar time periods 

in studies conducted in Connecticut, New York, 

and Pennsylvania). This study was conducted, 

immediately following the May – June 2005 Click It 

or Ticket high-visibility enforcement program. There 

were 9,707 observed occupants during the day and 

5,791 occupants observed during the night.

Daytime observations were made for 20 minutes at each 

location. Paired observers, one to observe and another 

to record, collected data. Survey teams observed and 

recorded information regarding occupant type (driver 

or passenger), vehicle type (passenger car, pickup 

truck, sport utility or van), sex (male or female) and 

Seat Belt usage (wearing or not wearing). Day of week 

and hour of day also were recorded, as was roadway 

type (Interstate, U.S./State highway or local road). 

Roadways were sub-classified as located inside or 

outside city limits. Only front-seat outboard passengers 

were observed.

Survey teams made nighttime observations at the same 

locations as the daytime observations and usually on 

the same day. However, the nighttime observation 

periods lasted 45 minutes in order to sample a 

sufficient number of vehicles given the lower traffic 

volume at night. In addition, nighttime observers 

used night vision technology. AutoGated brand night 

vision goggles (XR5 image-enhancing tube) were 

used in tandem with an infrared spotlight to provide 

adequate illumination of the vehicle occupants 

without affecting the occupants of the vehicle 

(infrared light is not visible to the naked human eye 

but is visible to the goggles).

Results

When belt use observations across all 108 sites were 

combined, daytime belt use (86.6%) was greater than 

nighttime belt use (80.4%), a statistically significant 

difference of 6.2 percentage points. 

Daytime versus Nighttime Belt Use (2005)

Occupant

For drivers, the rate of belted drivers was less at night 

(80.7%) than during the day (86.9%). The effect was 

similar for passengers – the rate of belted passengers 

was lower at night than during the day (Night: 81.1%; 

Day: 86.0%). 

75%

80%

85%

90%

Day Night

86.8%

80.4%

Traffic Safety Facts

Traffic Tech – Technology Transfer Series
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 Melissa 

Cheung, MPH, Editor, fax 202-366-7096, e-mail:

melissa.cheung@nhtsa.dot.gov. 

400 Seventh Street, SW., NTI-130

Washington, DC 20590

Sex

Both men and women wore their seat belts less at night 

than during the day. At night, men used their belts 

78.2 percent of the time, and 85.1 percent during the 

day. At night, women used their seat belts 86.3 percent 

of the time compared to 89.9 percent during the day. 

Vehicle

Seat belt use was lower during at night than during 

the day across all vehicle types: passenger cars (Night: 

80.9%; Day: 90.4%), pickup trucks (Night: 77.7%; Day: 

83.8%), sport utility vehicles (Night: 85.3%; Day: 

87.9%), and vans (Night: 87.9%; Day: 88.2%). Observed 

nighttime belt use rates were also particularly low in 

pickup trucks and high in SUVs and vans.

Roadway Characteristics

Outside city limits/rural locations, seat belt use was 

lower at night than during the day (Night: 77.6%; Day: 

84.7%). Inside city limits, seat belt use was also lower 

at night (Night: 83.1%; Day: 88.6%). 

Road Type

Regardless of road type, belt usage was lower at night 

than during the day. Belt use on interstates was 83.2 

percent at night and 88.1 percent during the day. Belt 

use on non-interstates was 79.6 percent at night and 

86.2 percent during the day. Seat belt use characteristics 

of those observed in New Mexico by day and night are 

summarized in the table.

Percentage Belt Usage at Day and Night (2005)

† For some observations, Sex and/or Vehicle type were not determined

Discussion

The results of the observational surveys presented 

here suggest that belt usage is lower at night than 

during the day. These results are similar to those 

reported by Chaudhary et al. (2005). Day/night belt 

use differences were consistent for men and women, 

for drivers and passengers, across road types, and for 

urban (inside city limits) and rural areas. The results 

of this study also suggest that the day/night belt use 

difference exists across vehicle types. 

The seat belt use figures reported here cannot 

necessarily be considered descriptive of the entire 

State of New Mexico. There was no weighting of 

the site-by-site results, necessary to make the data 

representative of the whole State. However, there is 

similarity of the current findings to a representative 

daytime and nighttime seat belt use study conducted 

in Connecticut, suggesting that the current findings, 

while descriptive, may mirror what is taking place in 

the the entire State.

How to Order

For a copy of Daytime and Nighttime , write to 

the Office of Behavioral Safety Research, NHTSA, 

NTI-130, 400 Seventh Street SW., Washington, DC 

20590, send a fax to 202-366-7096, or download from 

www.nhtsa.dot.gov. John Siegler, Ph.D. was the 

Project Manager.

Drivers

Passengers

OCCUPANT

Men

Women

SEX

Car

Pickup

CAR TYPE

Inside

Outside

CITY LIMITS

Interstate

Non-Interstate

ROAD TYPE

SUV

Van

75 80 85 90 95

Day (%) Night (%)