Driver Distraction: Results from Naturalistic Teenage Driving Studies Charlie Klauer, Ph. D. Research Scientist Group Lead: Teen Risk and Injury Prevention.

Driver Distraction:Results from Naturalistic Teenage

Driving Studies

Charlie Klauer, Ph. D.Research Scientist

Group Lead: Teen Risk and Injury PreventionCenter for Vulnerable Road Users

Virginia Tech Transportation Institute

Introduction

• Driver distraction, defined here as engaging in a secondary task or activity that is not central to the primary task of driving, has been shown to be a contributing factor for many crashes.

• Secondary tasks and other activities in which drivers choose to engage while driving is also known to be highly varied, including very complex activities (e.g., text messaging on a cellular device) to very simple activities (e.g., selecting a radio preset).

A New Method of Study:Large-Scale Naturalistic Driving

•40 to 100 drivers •No instructions•12 to 18 mos.•10,000’s of hours•2 MVMT

Driving Safety Research Approaches

• Epidemiological Studies• PARs• Simulation• Test Track• Lab Experiment

• Missing Piece?

4

NDS

Naturalistic Data Collection ApproachHighly capable instrumentation (well

beyond EDRs)• Multiple channels of digital, compressed

video• Multiple radar sensors front, rear and/or side• Machine vision-based lane tracker• Many other sensors: GPS, glare, RF,

acceleration, yaw rate, controls, etc.• Cell phone, wireless internet, or hardwire

download• Ties into vehicle networks to obtain other

information

Limitations…• Have not yet captured a large number of crash events• To overcome this limitation several studies have utilized

“near crashes” in combination with crashes. • Near crashes, in this case, are defined as having all of

the elements of a crash with the exception that the driver implements a successful evasive maneuver.

• The 100 Car Study showed that near crash involvement is correlated with crash involvement across differing drivers

• There is a growing body of evidence that combining crash and near crash events provides a valid measure of overall crash risk.

Results: Driver inattention is a key contributing factor in crashes for both truck and light vehicles.

• The largest single contributing factor is looking away from the roadway just prior to an unexpected event or condition. This accounts for somewhere between 70% and 90% of unsafe events.

• Engaging in activities that are unrelated to driving (i.e., “secondary tasks”) and external distractions account for most of the inattention-related risk. – High Risk: Looking away many times and/or long periods– Includes: Cell phone dialing, text messaging, Ipod/MP3

manipulation, and internet interaction. – Much less risk: Eating/drinking, talking to passengers, simple radio

functions, and even talking on a cell phone. • Teens are four times more likely to be involved in a near crash or crash

while performing a secondary task than their adult counterparts.

Analysis Approach

• Data analyses were conducted utilizing the “100 car” and heavy truck naturalistic driving databases.

• These data were specifically coded for the purpose of assessing secondary task distraction.

• From these data, an “event” database of crashes and near crashes was created with– 830 crashes, minor collisions and near crashes (100 Car)– 118 crashes, minor collisions, and near crashes (34 Truck)

• These data were also used to develop a “non-event” or baseline database to assess exposure.

• These results have significant design implications for driver-vehicle interfaces

– Cognitive-only, or auditory-voice secondary task interfaces will generally be less risky than visuo-manual secondary tasks.

– The tasks with the highest crash risk are those that require multiple glances away from the road.

Hand-held is substantially riskier than “true” hands-free.

• Operating a complex hand-held device is significantly more risky than a hands-free counterpart.

• Dialing and answering a hand-held phone were both higher risk tasks, even in comparison to the often longer task of talking on a hand held phone.

• Greatest proportion of risk does not come from the conversation or act of holding a phone to one’s ear, it comes from the complex task components of dialing, answering, texting, etc. that require multiple glances away from the roadway.

Cognitive versus Visual Distraction

• Conversation may be distracting but it does not translate into crashes/near-crashes– True for naturalistic data and crash database

data.• Visual distraction, eyes off forward

roadway increases crash/near crash risk– True for naturalistic data and controlled

experiments.

Future NDS

• SHRP 2– ~3000 participants

• Supervised Practice Driving Study– 90 teenaged drivers

• MSF 100 Motorcycle Study