Pre-Trip Tire Defect Under Delivery Deadline
You are the assigned driver of a 3.5-tonne closed van on a 5:00 AM delivery run. At 4:25 AM, during pre-trip inspection in light rain, you find the right rear inner tire has a fist-sized sidewall bulge and 2 mm remaining tread. The spare is a 15-inch wheel, but the van’s rear axle requires 16-inch tires. The van is loaded with 2.4 tonnes of cartons for a customer 30 km away; the delivery contract imposes a PHP 5,000 late penalty. Your supervisor says, “Use the spare-it is only 30 km, and we cannot lose that account.” The route includes a 4 km expressway stretch and a steep off-ramp. You have no tire service contact on site and the depot’s other van is already out. The rain is becoming heavier and the loading bay has no covered repair area.
1. Which defect should stop the trip, and why is the spare not an acceptable fix for this load and route?
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The controlling defect is the sidewall bulge, not the tread alone. A bulge indicates internal cord damage; under a 2.4-tonne load, at expressway speed, in rain, and with off-ramp braking, it can fail suddenly as a blowout. The 2 mm tread is also too shallow for reliable wet grip.
The spare is independently disqualifying: a 15-inch wheel on an axle specified for 16-inch tires creates a different rolling circumference. That causes continuous differential and axle wind-up, uneven braking, possible ABS misreading, and tire overheating. A one-inch diameter difference is far beyond any temporary-use tolerance. So neither the damaged tire nor the spare meets roadworthiness for this trip.
2. What sequence would you follow before the van moves, and what would you tell dispatch?
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- Do not move the van. Chock the wheels, switch off, and photograph the bulge, tread depth, and spare size.
- Record the defect on the pre-trip checklist and notify dispatch in writing: defect, spare mismatch, load weight, route risk, and weather.
- Request a matching 16-inch tire/wheel and tire service, or a replacement vehicle. Do not accept “just inflate it.”
- If no service is available, arrange transfer of the 2.4-tonne load to another vehicle. Reducing load does not make the damaged tire or mismatched spare legal.
- Give the customer a revised ETA and document the penalty discussion.
A factual message is best: “Vehicle unsafe: right rear inner tire sidewall bulge; spare is 15-inch but axle requires 16-inch. Cannot depart until matching tire or replacement vehicle is available.”
3. The supervisor insists: “Use the spare or find another job.” What is your response, and what do you document?
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Refuse to drive the van. State the specific hazard plainly: a sidewall bulge can blow out, and the spare’s diameter mismatch is not a temporary-use fix. Safety and roadworthiness obligations outweigh the delivery penalty.
Offer alternatives: call tire service, swap vehicles, or delay delivery with customer notification. If pressure continues, ask for the instruction in writing and escalate to fleet safety or HR. Document the time, names, defect, photos, your refusal, and the alternative arrangements. Do not sign a false pre-trip checklist. A contemporaneous record shows the refusal was based on an identifiable risk, not insubordination.