In-vehicle workload assessment: Effects of traffic situations and cellular telephone us

eBor-Shong Liua,*, Yung-Hui Leeb

Journal of Safety Research 37 (2006) 99 – 105學生 :莊靖玟

Methods - Participants

Twelve participants (6F， 6M) . The age of the subjects ranged from 25 to 45

years, average age was 35.2 years. All participants had held a drivers license for

at least two years and drove 5,000 km or more annually.

Each had owned a cellular phone for at least one year and regularly used it in vehicle.

Methods - Experimental vehicle Nissan Cefiro 3.0 Nokia 3310 Four CCD cameras Video-recorder system Portable ECG system, and an auxiliary Battery Microphone VHS recorder (Sony SL82K, Japan)

Methods - Heart rate measurement Heart rate was calculated from the ECG recor

dings by Cosmed software (Quark Windows 6.2)

Data were exported into Microsoft Excel for further analysis.

Resting heart rate subtracted from heart rate on driving with presence/absence of phone is defined as incremental heart rate.

Methods - On-road tests

★ Driver workload was measured in two traffic situations. First participants drove in each direction along a 7-km

section of a three-lane road in Taipei city (speed limit 50 km/h) with 24 signalized intersections, and numerous buildings on both sides.

In the second situation, participants drove in each direction along a 22-km section of National Highway No.3A (Taipei Connection Route) with four-lanes (speed limit 100 km/h). ★ The experiment was conducted during off-peak daylight hours (10 a.m.–12 noon and 2 p.m.– 4 p.m.).

Methods - On-road tests

Each driver was asked to perform four of the following phone-based tasks, with their sequence also randomly determined:

while driving on urban roa

ds

while driving on motorway

s

mathematical-addition

無 (task 1) (task 3)

有 (task 2) (task 4)

Methods - Measurement

(a) Driving performance: mean driving speed (km/h) SDSW (degrees) standard deviation of lane position (SDLP;cm) (b) Task performance: test scores consisted of response time (sec) proportion of correct answers (%) (c) Physiological responses: heart rate (HR; beats/min) incremental heart rate (DHR, beats/min)

Results

Results

Results