Article date 29 February 2016
Revised 02 March 2016

There is discussion concerning a suitable route for a railway line between Oxford and Cambridge. For a route via London, passengers from Oxford travel to Paddington, taking a train from King's Cross or Liverpool Street to arrive at Cambridge. With "Evergreen 3" proposals by Chiltern Railways, there will also be a route from Oxford to Marylebone via Bicester.

However, the focus of discussion is on a route serving towns in the Oxford to Cambridge arc, i.e. not via London. This discussion is being promoted by the East West Rail Consortium (EWRC) where this is referred to as the Central Section. Information presented in relation to the Central Section is educational and interesting.

Options are currently being studied by Network Rail. Network Rail distinguishes between corridors, which are broad, and specific routes in order to ensure for example that value-for-money studies are undertaken prior to drawing lines on maps. We quite understand that corridors are defined and compared prior to route selection. However it may also be that potential routes and their relationships to existing infrastructure may have an impact on corridor definition and selection. By analogy, there may be benefit in a modified waterfall model rather than a pure waterfall model. It is not clear to us if corridors include connecting chords, as do routes. It may be that two alternate routes are instantiations of the same corridor if they are topographically equivalent.

Options under investigation include a corridor from Bedford to Hitchin, potentially taking inspiration from the former line from Bedford to Hitchin, also a corridor via Sandy potentially taking inspiration from the former line from Bletchley to Sandy. In the latter case, a train from Oxford would either cross the ECML at Sandy and continue eastwards or connect onto the ECML southwards at Sandy to Hitchin, then making use of the existing line from Hitchin to Cambridge.

We have reservations regarding proposals that violate the Short Hop Principle (article TBA), (that is, of limiting the capacity on a lengthy railway line for the convenience of services that wish to use solely a brief portion of the line).

The following plan (diagrammatic map) illustrates three very different route options.

Option A is a route crossing the ECML to the south of St Neots, with a new station St Neots South as a station stop on the ECML and as an interchange station.

There is potential for a new station Bedford South. This would be within the Bedford conurbation and a station stop on the existing line from Bletchley to Bedford. It is unlikely that this would also be a station stop on the Midland Main Line. The purpose of Bedford South would be to provide a station stop in Bedford without the need for trains to call at the existing Bedford station and then change direction to continue their journey and which would also necessitate a new chord, not illustrated, to permit services between Bedford and Cambridge.

Option A would possibly require a new line around St Neots located to the east of the town so as to provide a connection between Oxford and Peterborough.

Option B is a variation of Option A with no new station stop on the ECML. There would be no new station St Neots South. Any connection between Oxford and Peterborough would be provided to the south of St Neots.

There is potential for a new station Bedford South, as for option A.

Option C describes a route from Oxford to Cambridge not via Bedford. The new line would probably branch off from the existing Bletchley to Bedford line somewhere to the east of the M1 motorway, not illustrated, so as to avoid construction of a new bridge over the M1. The new line would take inspiration from the A507 east-west road, with possible potential for rail-centric towns also accessed from the A507.

Various possibilities exist for connecting chords. Indeed, the extent to which new services could be envisaged leads us to suggest this new line might be referred to as a "service line". Chords illustrated are (i) Bedford to Cambridge via the Bedford to Bletchley line; (ii) as an alternative to (i), Bedford to Cambridge via the Midland Main Line; (iii) Luton to Cambridge; (iv) Oxford to Peterborough; (v) Oxford to Hitchin, potentially enabling Hitchin as a station stop for services between Oxford and Cambridge, where a change of direction would be necessary. This provides Hitchin as an interchange station between Oxford to Cambridge and the ECML. Not illustrated is a connecting chord for a service from Luton to Oxford, the journey being achieved by a change of train if Luton to Hitchin/Cambridge is provided.

Previously there has been a proposal for an Oxford to Cambridge route via Luton Airport and which is no longer being progressed. Option C provides the possibility of a new line southwards to Luton Airport from the new east-west line, potentially continuing to Ware on the line to Hertford East. This would for example enable a Crossrail 2 service via Luton Airport to Bedford or to Cambridge. Cost-benefit analysis would be necessary.

We have illustrated the new Oxford to Cambridge line approximately on a west-east orientation, with a chord southwards to Hitchin, the thinking being that trains using this chord would not connect onto the ECML prior to arriving at Hitchin.

An alternative to this would be a chord southwards that connects onto the ECML, such that a train to Hitchin connects onto the ECML prior to arrival at Hitchin.

An alternative is as follows. From Bletchley, cross the ECML then turn southwards to connect onto the existing line from Cambridge to Hitchin.

An alternative would be for the new Oxford to Cambridge line to run on an alignment, rather more north-west to south-east, to the south of Hitchin, turning northwards for arrival at Hitchin. Such a line would also run closer to Luton Airport.

Potentially an interchange station at the point where the Oxford to Cambridge line intersects with the ECML might be considered.

Potentially an interchange station at the point where the Oxford to Cambridge line intersects with the Midland Main Line might be considered.

Of the three options A, B and C presented here, we suggest that option C has the greatest potential.

It may be that option C is a new corridor : Bletchley and Bedford to Hitchin. Alternatively, it may be a route option for the Bedford to Hitchin corridor.

Requirements have been identified in a study by Atkins Consulting by prioritising journey pairs. We appreciate the work undertaken. Given that a picture is worth a thousand words, we find the illustrations towards the end of their Executive Summary report inspiring. The report is available here : executive summary (pdf opens in new window or tab). The illustrations are Figure 4 (Very High Priority journey pairs as identified in conditional outputs) and Figure 5 (High Priority journey pairs as identified in conditional outputs).

It is interesting to compare option C with these requirements. It is not necessarily the case that all connecting chords illustrated for option C would be implemented, although passive provision for future addition would add flexibility.

When comparing corridors, it may be that an assessment of flexibility for (possibly future) provision of connecting chords is a factor. Thus, for example, a comparison between option C and the Bletchley to Cambridge via Sandy corridor.

In terms of satisfying requirements, it would be interesting to consider whether there might be a case for an extension of the Dunstable to Luton and Luton Airport busway (we would have preferred light rail) to either Stevenage or Welwyn Garden City or both, co-existing with an Oxford to Cambridge rail corridor.

Option C would seem to imply three distinct routes for train services Bletchley to Hitchin, Bletchley to Bedford, Bedford to Hitchin although the second and third of these might be combined as a route for services Bletchley to Hitchin via Bedford.

Of the three options A, B and C presented here, we suggest that option C has the greatest potential.

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