An Open Access Journal
Table 7 Main assumptions for each identified KPI
KPI clusters | Individual KPI | Main assumptions |
|---|---|---|
IWT-related KPIs | Transport duration | Low fairway depth reduces overall sailing speed and increases transport time |
Fuel consumption | Low fairway depth causes higher fuel consumption A higher fuel consumption is directly related to higher transport costs | |
Transport supply | Low fairway levels reduce the loading capacity of vessels and simultaneously the transport supply in the market, which leads to higher transport costs Low fairway depths lead to increased sailing times, which results in lower loading capacity and leads to additional trips. Additional trips result in higher transport costs Loading capacity and transportation costs depend not only on fairway depth but also on vessel size | |
Transport costs | Low fairway depth decreases loading capacity per vessel and the total capacity that can be carried on a waterway within a given timeframe and, thus, increases transport costs Low fairway depths increase fuel consumption, which contributes to the increase of transport costs Both capacity and fuel consumption depend on water levels and the vessel type in use | |
Vessel draft | With low water depth, a vessel’s actual loading draft decreases accordingly Vessel draft and capacity depend on the size of the vessel used. In general, the larger the vessel, the larger the maximum loading draft | |
Transport emissions | Increased fuel consumption due to low fairway depth causes higher transport emissions | |
Market-related KPIs | Transport demand | The actual transport demand influences the net benefit generated by the rehabilitation of bottlenecks; if the transport demand shows a positive development, the net benefit of removing nautical bottlenecks is higher than if the market shows negative developments |
Modal share | In the short run, the effects of a modal shift to road and rail could be neglected, as they are insignificant In the long run, modal shift effects could be observed | |
Location-related KPIs | Throughput at bottleneck location | The higher the throughput at a bottleneck location, the higher the economic benefit of resolving this bottleneck The closer multiple bottlenecks are to each other, the less economic benefit can be achieved by resolving a single bottleneck |
Fairway depths | Fairway depth is essential to determining the criticality of a bottleneck’s location Fairway depth is linked to all other KPIs |