Table 2 Independent variables and their possible values

VMS

With, Without

DSD

With, Without

Entry rumble strips

With, Without

HWZ rumble strips

With, Without

Lane width

3.30, 3.00, 2.70 m

Road section

AWA, HWZ, noWZ

Run order

1, 2, 3, 4

Age

20–24, 25–29, Over 30 years old

Gender

Male, Female

Experiment

1, 2