8,700 Studies Reviewed. 87.0% Found Biological Effects. The Evidence is Clear.
Shield Your Body
Brain & Nervous System1,257 citations

Association between cellular-telephone calls and motor vehicle collisions.

Bioeffects Seen

Redelmeier DA, Tibshirani RJ · 1997

View Original Abstract
Share:

Cell phone use while driving quadruples crash risk, with hands-free devices offering no safety advantage over handheld phones.

Plain English Summary

Summary written for general audiences

Researchers analyzed phone records from 699 drivers who had been in car accidents to see if cell phone use increased crash risk. They found that drivers were four times more likely to crash while using their phone compared to when they weren't, with hands-free devices offering no safety advantage over handheld phones. The study suggests that the mental distraction of phone conversations, not just physical handling, creates the danger.

Why This Matters

This landmark 1997 study was among the first to scientifically demonstrate what many suspected: cell phones create serious safety risks while driving. What makes this research particularly compelling is that it measured actual phone usage through billing records rather than relying on driver self-reports, eliminating recall bias. The finding that hands-free devices offered no protection reveals that the primary hazard isn't physical manipulation of the phone, but cognitive distraction from the conversation itself. This research helped establish the foundation for distracted driving laws worldwide and demonstrates how wireless technology can create indirect health and safety risks beyond the biological effects of electromagnetic radiation. The study's methodology has been replicated numerous times, consistently showing similar results across different populations and time periods.

Exposure Information

Specific exposure levels were not quantified in this study.

Study Details

Because of a belief that the use of cellular telephones while driving may cause collisions, several countries have restricted their use in motor vehicles, and others are considering such regulations. We used an epidemiologic method, the case–crossover design, to study whether using a cellular telephone while driving increases the risk of a motor vehicle collision.

We studied 699 drivers who had cellular telephones and who were involved in motor vehicle collisions...

A total of 26,798 cellular-telephone calls were made during the 14-month study period. The risk of a...

The use of cellular telephones in motor vehicles is associated with a quadrupling of the risk of a collision during the brief period of a call. Decisions about regulation of such telephones, however, need to take into account the benefits of the technology and the role of individual responsibility.

Cite This Study
Redelmeier DA, Tibshirani RJ (1997). Association between cellular-telephone calls and motor vehicle collisions. N Engl J Med 13;336(7):453-458, 1997.
Show BibTeX
@article{da_1997_association_between_cellulartelephone_calls_2534,
  author = {Redelmeier DA and Tibshirani RJ},
  title = {Association between cellular-telephone calls and motor vehicle collisions.},
  year = {1997},
  doi = {10.1056/nejm199702133360701},
  url = {https://www.nejm.org/doi/full/10.1056/nejm199702133360701},
}
DOI: 10.1056/nejm199702133360701

Cited By (1,257 papers)

View all 1,257 citing papers on Semantic Scholar

Quick Questions About This Study

Yes, drivers are four times more likely to crash while using their phone compared to when they're not, according to a 1997 study of 699 drivers. The research found a relative risk of 4.3, meaning phone conversations quadruple your collision risk during calls.
No, hands-free phones offer no safety advantage over handheld phones while driving. The 1997 study found hands-free devices had a relative risk of 5.9 compared to 3.9 for handheld phones, showing mental distraction creates the danger, not physical handling.
Crash risk remains elevated for at least 5 minutes after making a call. The study found calls within 5 minutes of collision had a relative risk of 4.8, compared to 1.3 for calls made more than 15 minutes before the accident.
Yes, having a cell phone provides benefits after crashes occur. The study found 39% of drivers called emergency services immediately after their collision, suggesting phones offer important advantages in the aftermath of accidents despite increasing crash risk during use.
No, driving experience doesn't protect against phone-related crashes. The 1997 research found the four-fold increase in collision risk was similar across drivers of different ages and experience levels, showing phone distraction affects all drivers equally during conversations.