While navigating a secondary route following a severe winter storm, a commercial driver approaches an older railroad overpass marked with a posted clearance of 14 feet 0 inches. Recent unposted highway resurfacing added 4 inches of asphalt to the roadway, and an additional 3 inches of hard-packed snow and ice has accumulated under the span. If the driver's unladen semi-trailer has a measured standing height of 13 feet 8 inches, which course of action must the driver take?
- AMaintain normal approach speed and rely on emergency braking only if roof contact appears imminent, assuming perception distance provides adequate stopping margin.
- BSteer sharply onto the shoulder to pass under the structure at an angle, disregarding trailer off-tracking and variable bridge heights.
- Stop before reaching the overpass and take an alternate route, because resurfacing and ice accumulation have reduced physical clearance below the vehicle's height.Answer
- DRestack onboard freight toward the upper roof bows to compress the suspension springs, ignoring the increased rollover hazard from an elevated center of gravity.
Answer
Stop prior to entering the structure and select an alternative route, recognizing that pavement resurfacing and packed ice have reduced the actual vertical opening below the trailer height.
The combination of 4 inches of new paving and 3 inches of packed ice reduces the original 14-foot 0-inch clearance down to 13 feet 5 inches. Because the unladen trailer stands at 13 feet 8 inches, the vehicle is 3 inches taller than the physical opening. The driver must stop and take an alternate route to prevent a collision.
Step-by-Step Solution
Key Concept
Overhead Clearance Dynamics and Road Surface Variations
Estimated Time:1m 30s