Institute research documented that all-driver bans on hand-held phone conversations can have large and lasting effects on phone use. Based on observations of drivers conducted up to seven years after bans were implemented in New York, the District of Columbia and Connecticut, the rates of driver hand-held cellphone conversations were an estimated 24-76 percent lower than would have been expected without a ban.
In the Institute's 2009 telephone survey about cellphone use, 56 percent of drivers in states with bans reported they use phones when driving, compared with 69 percent in states without such laws.
The proportion of drivers who talk on phones and always talk hands-free was 22 percent in states with all-driver bans on hand-held phones and 13 percent in states without all-driver bans.
Phone bans seem to have less effect on younger drivers. Since Dec. 1, 2006, North Carolina has banned the use of any telecommunications device by drivers younger than 18. Eleven percent of teenagers leaving high schools in the afternoon were using phones prior to the ban, and this did not change significantly when measured five months after the restriction took effect or two years later.
There is scant information on drivers’ compliance with texting bans. The Institute’s 2009 survey of drivers found that among 18-24 year-olds — the group most likely to text — 45 percent reported texting while driving in states that bar the practice, just shy of the 48 percent of drivers who reported texting in states without bans.
Among drivers ages 25-29, 40 percent reported texting in states with bans, compared with 55 percent in states without bans.
High-visibility enforcement campaigns may be one way to increase compliance with cellphone and texting bans. After programs of publicized, high-intensity enforcement of hand-held cellphone and texting bans were implemented, the number of drivers observed holding a hand-held phone to their ear declined by 57 percent in Hartford, Conn., and did not decline in a comparison community. Observed hand-held phone conversations went down 32 percent in Syracuse, N.Y., but also declined 40 percent in a comparison community; both changes were significant. Observed manipulation of hand-held phones (e.g., dialing, texting) decreased significantly in both cities following the enforcement initiative and did not decrease in the comparison communities.