Tanks and other armored vehicles are not generally recommended for long-distance travel, as their excessive fuel consumption, noisy operation, and limited mobility make them easy targets for hordes of zombies. Additionally, the difficulty of finding replacement parts and a technician skilled enough to work on the vehicle limits their use to organized military.
School buses and vans can be modified to be highly effective when a larger group is in need of mobility, though this assumes roadways remain clear.
Vehicles specifically suited to off-road use, as well as dirt bikes and even bicycles, can be effective transportation when road conditions are unknown and mobility is of the utmost importance.
Pickup trucks are the most effective vehicles in the case of a zombie outbreak. They possess good handling and speed, as well as great mileage and payload. Pickup trucks are also better suited for off road terrain than buses or vans, while still maintaining a high carrying capacity.
Pickup trucks can also be fitted with snowploughs, which can be useful for breaking up dense clusters of zombies.
The transportation items may include bicycles with off-road tires, emergency tools, spare auto parts (e.g., fuses, fan belts, light bulbs, head light, tire pump, etc.), and an inflatable raft with paddles.
It may be possible that gas become hard to find (Mad Max), limiting your ability to move and find a durable shelter. You may fill as much tanks as possible as soon as the start of the outbreak.