An ‘Orbital’ route around Cambridge, or an ‘outer ring road’, could enable rapid movement around the City periphery, and help to avoid unnecessary journeys into the centre. This could make cross-city journeys more efficient and thereby help reduce congestion.
The core of an ‘Orbital’ in the north and west is already in place with the M11 and A14 highways, which are probably already being used by many to avoid the city centre when making cross-city journeys. The routing in the east and south of the City is less clear, and Cambridge Connect has not yet evaluated what route, if any, might be suitable as an ‘Orbital’ in this region.
Cambridge Connect recognises that an Orbital route around the City of Cambridge, a kind of outer Ring Road, is an attractive concept. Should it be pursued, the Orbital could take different forms depending on needs and constraints. For example, along the M11 the Orbital route may comprise no more than the main highway without modification, while along the A14 it may comprise a dedicated lane for buses. The mix would depend on needs, and this would be determined by detailed traffic demand analyses weighed against other considerations. Existing main transport corridors offer the most immediate practical routes, minimising costs and environmental and social impacts.
Much as the Orbital concept has many merits, Cambridge Connect believes that should a Cambridge Light Rail system be established, much demand for Orbital bus services would be satisfied by the faster and more convenient Light Rail alternative. This can be illustrated by the arguments set out below in relation to recent proposals put forward by the Greater Cambridge City Deal for a ‘Western Orbital’.
‘Western Orbital’ proposals
The City Deal concept of a ‘Western Orbital’ is defined more specifically as a public bus service running either as an off-road ‘dedicated busway’ alongside the M11 between J11 and J13, or it could run on the M11 itself, either with or without a dedicated lane. It would link to the existing guided busway extending from Trumpington to Addenbrookes, and in due course to a further bus link through the new housing development in the NW of Cambridge (Eddington), Darwin Green and to the Science Park. This is more arc than orbital, although the implication is that it might eventually form part of an orbital route completely encircling Cambridge. Public consultation on this concept ran through until 21 March 2016.
In the context of the Cambridge Light Rail proposals by Cambridge Connect, and in particular if the Isaac Newton Line was implemented, some questions arise over whether a ‘Western Orbital’ would be a wise investment. In particular, the Isaac Newton Line would enable a journey time from High Cross (West Campus, location of the present Madingley Park & Ride) to Addenbrookes of ~13 mins, and only ~11 mins from The Cavendish. This compares to a journey time of 15-16 minutes on a dedicated busway between the same points over a route alongside the M11, or 18-19 minutes if utilising only the M11 highway.
There is, however, another very important dimension to journey decisions: satisfying multiple purposes on a single trip. Any journey along the proposed ‘Western Orbital’ necessarily would be limited in purpose: i.e. to get from Point A to Point B, as there are few other ‘attractions’ along the route (OK, maybe Waitrose!). In practice, people are likely to find a route more attractive if it enables them the choice to satisfy several objectives on the same journey. For example, the Cambridge Light Rail option enables people to travel from West Campus to Addenbrookes and call in at their College, and shop in the Market, and meet their friend departing at Cambridge Rail station, along the way. The flexible options are powerful incentives for users to choose this route; not only is the journey time by Light Rail faster than the suggested bus route, it enables more choices. It is doubtful whether a ‘Western Orbital’ would attract enough patronage to be viable in these circumstances.
Recognising that Cambridge Light Rail might not gain support for some time, there could be merit in a ‘Western Orbital’ in the interim specifically to service journeys between the West Campus and Addenbrookes. However, data are lacking on the demand for this ‘single purpose’ link, and it remains unclear whether this route would need to be subsidised to be viable. It seems unwise to invest in major built infrastructure for the proposed ‘Western Orbital’ route at this stage, and a light-touch approach using the existing M11 would seem a prudent and cost-effective approach.