Very Narrow Aisle vehicles operate in aisles with little free space between the vehicle and the rack or the overhanging loads. Travel speeds can only be maintained if the operator is free to concentrate on the hydraulic and travel functions. Steering controls within the aisle are part of the "Guidance System". Rail guidance via the vehicle mounted guide rollers and angle iron mounted within the aisle. Wire Guidance requires vehicle electronics and a floor embedded wire to follow.

In general there are two types of guidance: Rail Guidance and Wire Guidance both have their benefits.

Rail Guidance

As can be seen in the picture, rail guidance is a method in which the vehicle travels between angle iron rails mounted on both sides of the working aisle. A set of four guide rollers mounted on the vehicle maintain the path. The steer wheel is centered electronically in order to prevent oscillation back and forth between the rails; entry guides assist the operator to enter the aisle and optical sensors provide automatic aisle identification - releasing optional travel and hydraulic functions.