# Randomized trial on mobile technology to reduce young drivers’ cellphone use

> **NIH NIH R01** · RESEARCH INST NATIONWIDE CHILDREN'S HOSP · 2021 · $640,819

## Abstract

PROJECT SUMMARY
While motor vehicle crash risk is 2-6 times higher for all drivers engaging in cellphone use, cellphone use while
driving is most prevalent among young drivers (18-24 years). Young drivers have both the highest phone use
while driving and the highest crash rate per capita among all ages, but they are understudied. Technological
solutions, including cellphone-blocking apps and driving mode (e.g., Apple’s “Do Not Disturb While Driving”),
may be promising, but research on effectiveness remains sparse. Our pilot R21 found that a commercial app is
effective in reducing cellphone use while driving, but had insufficient power to examine high-risk driving events.
Few studies have examined driving mode or compared driving mode with a commercial app in reducing phone
use and high-risk driving events. Therefore, we propose an R01 with objective to conduct a randomized
controlled trial to determine the effects of a cellphone app and a driving mode intervention in reducing
cellphone use and high-risk driving events in drivers aged 18-24 years. We hypothesize that cellphone use and
high-risk driving events can be substantially reduced if a cellphone app or driving mode is active. We also
hypothesize that the driving mode is as effective as the app. The aims of this project are to estimate the effects
of the phone app and driving mode interventions in reducing calling, texting, and handheld phone use (Primary
Aim 1), determine the effects of the phone app and driving mode interventions in reducing high-risk driving
events (Primary Aim 2), and pilot test the feasibility of tracking traffic violations and crashes using existing
databases (Exploratory Aim 3). A prospective, randomized, parallel-group, three-arm trial will be conducted. A
total of 1,200 young drivers will be randomized to receive: (1) a commercial app (active FleetSafer) that blocks
handheld phone use while driving, but allows emergency calls and phone use after pressing the passenger
button; (2) a driving mode (provided by the cellphone manufacturer or service provider) that blocks handheld
phone use while driving, but allows emergency calls and manual override or (3) an inactive FleetSafer app that
permits and tracks calls and texts (controls). Participants will be studied for six months (month 1: baseline,
month 2-6: intervention). The outcomes will include: (1) calling and texting while driving tracked by FleetSafer,
and (2) handheld phone use while driving and high-risk driving events captured by a video camera. We will
estimate the effectiveness of the app and driving mode interventions in reducing calling, texting, and high-risk
driving events. Guided by our preliminary R21, this study is innovative as we focus on novel technological
approaches to address the epidemic of cellphone-related distracted driving. We will employ proven video
capture methods to identify high-risk driving events and assess the contribution of cellphone use. This study is
significant, because the find...

## Key facts

- **NIH application ID:** 10209174
- **Project number:** 1R01HD102439-01A1
- **Recipient organization:** RESEARCH INST NATIONWIDE CHILDREN'S HOSP
- **Principal Investigator:** Motao Zhu
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $640,819
- **Award type:** 1
- **Project period:** 2021-06-01 → 2026-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10209174

## Citation

> US National Institutes of Health, RePORTER application 10209174, Randomized trial on mobile technology to reduce young drivers’ cellphone use (1R01HD102439-01A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10209174. Licensed CC0.

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