No spare does not mean there is only one answer. The safest option depends on where the truck is stopped, the type of failure, whether the vehicle can move without damage, and what service is available.
Option 1: Call mobile commercial tire service
A technician may bring a compatible tire and the equipment needed for an on-site assessment or replacement. Give the axle position, tire size, highway or facility location, and access details.
Option 2: Move only if it is safe and permitted
If the tire is losing air or visibly damaged, do not assume a short drive is harmless. Follow company policy, vehicle guidance, road rules, and a qualified professional’s direction; do not limp a truck on a flat tire.
Option 3: Arrange a tow or recovery
A tow may be needed when the truck is in an unsafe position, the wheel or suspension is damaged, the location cannot support roadside work, or the correct tire is not available.