Table 1 Components relevant in scope of RoRo maritime connectivity and data availability

Vessel capacities

Jiang et al. (2015), UNCTAD’s LSCI, Wang and Cullinane (2008).

Not straightforward. Capacity is not a good proxy of costs as the capacity is shared by passenger cars and trucks.

Service frequency

Indirectly in UNCTAD’s LSCI (as number of services) and Lam and Yap (2011).

Relevant. A higher service frequency reduces the waiting times for users and increases their transport options and hence generalized transport costs.

Number of vessels on service

UNCTAD’s LSCI

Not relevant as long as service frequencies are included.

Number of liner services / directly connected ports

Tang et al. (2011)

The number of directly connected ports is relevant. More destinations reduce generalized transport costs for users.

Number of service providers

UNCTAD’s LSCI, Bang et al. (2014).

Relevant. The relevance of the number of service providers relates to the benefits of competition. In some markets (e.g., UK to Spain) road transport may be a competitive alternative, in other markets (e.g., the Channel crossing) rail may compete, but these alternatives are never perfect competition. Two competing service providers are perfect substitutes. Thus, ‘ceteris paribus’ competing service providers lower the prices of service providers.

Transit time

Jiang et al. (2015)

Not straightforward. There is a trade off between transit times and tariffs. The only improvement of transit time without associated higher fuel expense is a reduction in the number of intermediate stops, which is included in the indicator developed in this paper.

Distance

Not straightforward. In a ‘gravity model’ approach, it can be argued that connections to distant destinations are less relevant that connections to close destinations. However, in the case of RoRo, the RoRo part is only one components of a door-to-door journey, so the ports cannot be treated as destinations (in comparison, such an approach does make sense for airports).