Drive 2 initiative

1) EU project concerned with developing vehicle monitoring equipment. See also Project Samovar.

Drink-driving limit

1) Statutory limit in UK for alcohol in the breath of vehicle drivers above which it is illegal to drive or be in charge of a motor vehicle (currently 35 mg of alcohol in 100 ml of breath, which equals 80 mg of alcohol in 100 ml of blood or 107 mg of alcohol in 100 ml of urine – RTA 1988 s11{2}).

Drawbar trailer/combination

1) Trailer with four or more wheels drawn by a rigid vehicle to form a drawbar combination. Currently in UK may be up to 32,520 kg maximum gvw and 18 metres long (to be increased to 18.35 metres).

DPP

1) Direct product profitability. Concept where all the costs relating to an individual product (eg material, manufacture, packaging, delivery, etc) to provide comparisons and identify inefficiencies in product marketing.

Double reduction axle

1) Vehicle rear axle with gearing (ie crown wheel and pinion – differential) designed to provide normal and lower drive ratio. Also double reduction hubs – in heavy goods vehicle to reduce stress on differential and half- (ie drive) shafts. See also Hub reduction.

Double-drive/bogie

1) On heavy vehicles with two or more rear axles, where at least two of the axles forming a bogie are driven (as opposed to trailing axle/s which is/are not driven). This gives improved traction (eg for use on rough/steep terrain).