The Effects of Commercial Electronic Variable Message Signs ...

Variable Ref. # Advantages Disadvantages
2.1.1 Category: two-lane
rural; collector; arterial;
freeway
2.1.2 Lanes: number;
width; markings; medians;
shoulders; rumble strips
2.1.3 Speed: posted;
advisory; 85 th percentile;
median
2.1.4 Condition: dry, wet,
ice, rain; oil slick
2.1.5 Traction: coefficient
of friction
2.2 Complexity 15
13, 15
71, 54
Important determinate of
driver workload.
50 Changes urgency of correct
driving responses.
Important to driver control
over vehicle.
43
Many variations even in
single category.
Less important.
2.2.1 Tangent: level; grade Less important.
2.2.2 Curve: horizontal;
vertical
2.2.3 Intersection:
signalized; stop controlled
2.2.4 Interchange: exit,
entrance, merge, gore
13, 44,
118
129,
38, 48
26, 44,
32, 48
May place sudden demand on
driver attention.
Increased driver workload. Wide variety of intersection
complexities.
Controlled access. More
carefully engineered.
2.2.5 Driveway; entrance Less important.
2.2.6 Lane change: merge;
diverge; lane drop
2.2.7 Other: bicycle lane;
fire house
2.3 Traffic 158,
38, 15,
113,
May place sudden demand on
driver attention.
Less important.