These regulations constrain the height to which loads can be stacked on a vehicle to minimize the risk of operatives being injured. The doubledecking of vehicles can help to relax this constraint without compromising safety, though only where vehicle height clearances permit.
Working time restrictions
Legal restrictions on drivers’ hours and working time, which are also a form of health and safety regulation, can constrain the amount of freight that can be collected and/or delivered in a single shift. In particular, they can reduce the amount of time available for backhauling and hence increase the proportion of empty running. It was feared that the application of the Working Time Directive to European road freight operations in 2006 would frustrate efforts to improve vehicle loading. In reality, European governments have tended to adopt quite a liberal interpretation of ‘periods of availability’ in WTD regulations, giving vehicle operators greater flexibility than they had initially expected. Based on the UK experience, the WTD appears not to have had the adverse effect on vehicle utilization than some commentators were predicting.
Capacity constraints at company premises
The size of an order is often constrained by the amount of storage capacity available at the delivery point. In some sectors, this storage capacity has been shrinking, partly in line with the downward pressure on inventory but also to intensify the use of floor space. Retailers, for example, have been compressing back-storeroom areas in their shops to maximize the floor area available for product display and merchandizing. Where deliveries are to warehouses, the dimensions of slots in the racking systems can dictate the maximum pallet height. Under these circumstances, the size and shape of unitized loads may optimize space utilization in the warehouse but not in the delivery vehicle (AT Kearney, 1997).
In some sectors, such as chemicals and agriculture, lack of investment has prevented the ability of tanks and silos to increase in line with vehicle carrying capacity. Expanding their capacity would improve vehicle utilization and often yield a healthy return on investment. Where companies have deliberately scaled down their storage space at the expense of transport efficiency, it may be necessary to reappraise the cost trade-offs in the light of rising transport costs and environmental concerns.
Conclusion
It has been suggested that if all trucks had glass sides, people would be surprised by the amount of air they carried. This chapter has tried to show that the under-utilization of vehicle capacity has many causes and can sometimes be justified on solid commercial grounds. Companies cannot afford to be complacent, however, in the way that they manage this capacity. In response to a combination of economic and environmental pressures they are now giving greater priority to vehicle fill and trying much harder to overcome the traditional constraints on load size and weight. This requires an internal realignment of business objectives within companies as well as greater external collaboration along and between supply chains. Advances in vehicle, materials handling and information technology can assist efforts to improve loading, as can investment in more storage space at critical points in the supply chain. As discussed more fully in Chapter 17, government also has a role to play by optimizing vehicle size and weight limits for sustainable distribution, adopting charging mechanisms that incentivize efficient loading, and running best-practice programmes for road freight operators.
A sample of 100 logistics specialists recently surveyed in the UK predicted that by 2020 the proportion of truck kilometres run empty would drop by 19 per cent and the average payload weight on laden trips increase by 12 per cent (Piecyk and McKinnon, 2009). This confirms that the potential exists to achieve substantial improvements in vehicle loading and reap the resulting economic and environmental rewards.
