The Hyder Report
3. REVIEW OF TRAMS FOR BATH PROPOSALS
Outline Description of The Trams for Bath Proposals
3.1 The Trams for Bath Proposals (TfB) are to construct and operate a new tramway serving most parts of the City of Bath and extending into some adjacent villages. This section briefly describes the tramway system as proposed by TfB. Eleven routes are proposed from the City Centre along five main radial routes as follows:
|
|
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| Western Riverside to | Upper Weston |
| Newbridge Park and Ride | |
| Twerton | |
| Lower Bristol Road (A36) | Oldfield Park |
| Southdown | |
| Whiteway | |
| Wells Road (A367) | Odd Down Park and Ride |
| Coombe Down | |
| North Parade Road | University Park and Ride |
| Bathampton | |
| London Road (A4) | Batheaston |
| Bathford | |
| Lansdown Road | Lansdown Park and Ride |
3.2 In the City Centre all tram routes would operate around a
circular route via Upper Borough Walls, Bridge Street, Grand Parade,
Pierrepont Street, Manvers Street, Dorchester Street, St James's
Parade, Westgate Buildings and Sawclose. An alternative route
would use Somerset Street, and Avon Street including some land
currently used for car parking on Corn Street. The proposal is
for trams to operate around the single-track loop in a clockwise
direction although anticlockwise operation could also be considered.
3.3 The detailed proposals for the system are described on the Trams for Bath website at 'http://www.bathtram.demon.co.uk'. The website covers system layout, the City Centre circle, individual route descriptions, route lengths, future extensions, fares, service frequency, appearance and technology of the vehicles, track, signalling, depot sites, capital costs, operating costs and revenue.
3.4 The total route length is given as 40 km of which 36 km are on street, 2.5 km are on reserved track and 1.5 km on grassed track. It is assumed that the system would be single track with passing places except on Wells Road where a 1.5 km section of double track is specified. Service frequency is given as a maximum of 10 trams per hour or 6 minute headway, with a 7.5 minute headway on most routes or 3.75 minute headways on combined routes.
3.5 A number of possible vehicle types are given but the 'TRAM' vehicle, currently under development by the TRAM Project Group at Blackpool, is suggested as the most likely choice. Replica historic vehicles could also be considered for tourist services. The criteria for a depot site are given but no specific locations are suggested.
3.6 The total capital cost of the system is given as £71 million. Annual operating costs are estimated at £10 million. A 'break even' single journey fare is given as £0.55 for a low fares assumption or £1.62 for a high fares assumption.
The TfB proposals for a tramway system for Bath is based extensively on the tramway that operated in Bath between 1904 and 1939. The proposed Bathford and Coombe Hill routes are almost identical to the original tram routes and those to Oldfield Park, Newbridge and Weston incorporate significant parts of the original system.
The proposed routes to Bathampton, University, and Lansdown would be entirely new and those to Odd Down, Whiteway, Twerton, Weston and Larkhall extend beyond the original network.
3.9 It is argued by TfB that the pattern of development of Bath has remained relatively stable because of the geographic and historic limitations on its expansion. The form of the original tram network is therefore still relevant. Hyder agrees this may be partly true, but it does not necessarily follow that a tramway is the most effective form of public transport for the present urban area, current travel patterns and traffic conditions.
3.10 The objective, or transportation function, of the TfB proposal is not actually stated but would appear to be to provide for the majority of local public transport journeys in Bath including all the Park and Ride journeys. It is envisaged that it would replace the majority of local bus routes. There would however still be a need for bus services to some areas which would not be served by the tramway or where the tramway would not provide the same level of accessibility.
3.11 The existing population of the City of Bath is about 80,000 and it is estimated by TfB that 72,000 people reside within 500m of a proposed tram route. This figure includes some areas such as Batheaston and Bathford which are not included in the population for Bath but it may be assumed that about 80% of the population could potentially be served by the tramway. It must be borne in mind that this does not take account of gradients which would substantially reduce the catchment area in many locations.
3.12 TfB suggest that there would be about 80 tram stops on the system, equivalent to a stop spacing of about 500m. This compares with over 250 bus stops on the existing bus network, probably at about 350m to 400m spacing, indicating that accessibility to the tram network would be significantly lower than to the bus network. However it is generally found that passengers will walk further to a rail-based system and hence a longer stop spacing and larger catchment area may be assumed than for an equivalent bus based system.
3.13 The proposed tramway network would link most of the major residential, commercial, retail and cultural parts of the city and would serve the two university campuses and the major hospital at Weston. It would serve the railway station and bus station in the City Centre. It would assist central area distribution. It would also serve the important development area of Western Riverside. It would therefore contribute towards many of the Council's policies relating to transportation and planning.
3.14 It would also be consistent with the government's policies as set out in the Integrated Transport White Paper:
Proposed Routes
3.15 Each of the proposed routes in the network is described on the TfB website. The following paragraphs comment on the routes and highlight some of the problems that do not appear to have been addressed by TfB.
Upper Weston and Newbridge
3.16 The route runs on street on New Street, James Street and Norfolk Buildings then on reserved track through the Western Riverside development. An alternative alignment would enter reserved track a little earlier through the superstore car park. This would be preferable provided that there was no interference from car park traffic. A route for a transit system is shown in the Urban Design Strategy for Western Riverside and this would create an excellent segregated spine route. A ìHomebaseî hardware store has recently been built on part of this alignment but it should be possible to adjust the transit alignment to the north or south of the building, or relocate the building in whole or part.
3.17 At Windsor Bridge Road the TfB tramway route turns north to join Upper Bristol Road and the remainder of the routes to Newbridge and Weston are on street. A major traffic objective on the Weston route is the Royal United Hospital. The tram route continues to Upper Weston although traffic potential at the northern end of the route would be small and the carriageway is steep and narrow. The TfB Newbridge route continues along Newbridge Road to terminate at the existing Park and Ride site. There is very limited scope for segregation within the highway on either route.
3.18 An alternative alignment could be feasible between Windsor Bridge Road and Newbridge using the former railway. Some buildings have been erected on this alignment but it may be possible to create a single-track route, if necessary by acquiring some properties. This would have the great advantage that a segregated route could be provided between the Park and Ride site and the City Centre. Some intermediate stops could be included. The TfB proposals include a tramway loop along part of Brassmill Lane to serve a relocated Park and Ride to the south of Newbridge Road. This site would be accessed directly from the former railway route. The Council is considering designating the former railway route as a transport corridor.
3.19 Reference is made to the possible extension of the Avon Valley Railway to Newbridge. It should be feasible to include a railway station as an interchange with the tram terminus and Park and Ride facility, if this extension is constructed at some future date. Alternatively in the longer term it would probably be technically feasible to extend the tramway westwards using the former rail alignment through Mangotsfield and Fishponds to create a link with the proposed light rail system for Bristol, thus providing a new Bath to Bristol rail service. It should be possible to retain a cycleway alongside the tramway.
Twerton
3.20 A third route uses the Western Riverside alignment to reach Twerton. After crossing Windsor Bridge Road it runs through an industrial estate, where some demolition may be necessary, to cross lower Bristol Road and join the former Somerset and Dorset railway alignment. It then follows road alignments to reach High Street and terminate on Newton Road. There are a number of narrow sharp turns, which would make this route difficult to develop and slow to operate. It would however serve some lower car ownership areas with a substantial proportion of segregated route.
3.21 Part of the former Somerset and Dorset railway has been landscaped and converted to a linear park. This section also passes very close to residential properties and there could be some adverse environmental impacts.
3.22 If all three routes were constructed and trams operated every 6 minutes on each, the frequency through Western Riverside would be every two minutes. It is suggested by TfB that the minimum headway would be 3.75 minutes which implies that trams would only operate every 12 minutes. Given the relatively short journey times, service frequency is likely to be a significant determinant of patronage.
Oldfield Park, Southdown and Whiteway
3.23 The first part of the Oldfield Park route follows the original tramway alignment with some modifications to take account of the new traffic layout at Churchill Bridge. It is proposed to use the existing footbridge and stated that little modification would be needed. A sketch diagram is included to indicate the proposed routes and location of additional traffic signals. An engineering assessment would be needed to confirm whether this arrangement is feasible and to investigate how the existing traffic signals and gyratory could be modified to allow for the tram movements.
3.24 There is a narrow bridge with 4m headroom at Lower Oldfield Park, which would limit the type of vehicle used and which would need to be traffic signal controlled. Most of the roads used by this route are relatively narrow residential roads with very limited opportunities for any form of reservation. Much of the route has frequent junctions and sharp radius curves which would reduce operating speeds and there are some significant gradients.
3.25 The route does serve an area with below average car ownership and could be expected to attract moderate levels of patronage. However the existing bus services provide reasonably frequent links to the City Centre and tram journey times are unlikely to be significantly lower.
Coombe Down and Odd Down
3.26 The Coombe Down route follows the original tram route throughout
with an additional spur at Odd Down to serve the Park and Ride
site. It follows Wells Road and Wellsway A367 and climbs about
130m in 3 km, an average gradient of about 4%. The route leaves
the City Centre at the same point as the Oldfield Park route and
similar comments apply regarding the need to establish how existing
traffic arrangements could be modified to incorporate the tramway.
3.27 There are some existing inbound bus lanes on Wells Road but the varying carriageway width prevents these from being continuous and they could not be used to provide a segregated single track. Wellsway is wider and is dual carriageway between Hatfield Road and Mitford Road. This is one of the few sections where it would be feasible to provide some form of segregation. The remaining sections to Coombe Down and Odd Down are single carriageway with limited opportunities for any segregation. Much of the Coombe Down route is only about 7m wide and single-track operation would not be practicable.
Bath University
3.28 The route leaves the City Centre circle
along North Parade, which is a two lane single carriageway with
no opportunity for segregation. It is already a major traffic
route into the central area and is likely to remain heavily used,
particularly if traffic restrictions are imposed on Manvers Street
or Dorchester Street. Previous studies suggested alternative routes
using either Pulteney Bridge which is already restricted to buses
or a new transit only bridge via South Parade. It may be feasible
to provide some priority on Pulteney Road, although existing traffic
flows are high and significant traffic restraint could result.
3.29 The University route then turns sharply into Bathwick Hill
where the existing junction would need to be remodelled. There
is a continuous gradient between 8% and 10% for nearly 2km up
Bathwick Hill. The lower section has a wide carriageway, which
could accommodate reserved track in the centre, but the upper
section is narrower, particularly along Oakley. The alternative
route along The Avenue may provide a more direct route into the
University and offer some scope for segregation.
Bathampton
3.30 The Bathampton route uses the same alignment as the University route to Bathwick Hill junction and then continues along Darlington Street before turning right into Sydney Place and Sydney Road. Most of this section has parking on both sides of the carriageway and it may be feasible to provide reserved tracks on one or both sides. Some wider traffic management measures including Beckford Road may be needed.
3.31 The route then continues along Warminster Road where a roadside reservation could possibly be provided. The final section along Bathampton Lane into Bathampton High Street is narrow with no scope for any segregation. The alignment at the junction with the A36 is difficult with restricted sightlines and traffic signal control would be necessary.
3.32 There is very little development along this corridor and the residential properties are associated with high car ownership. Potential demand from this area may be low, but it is likely to be greater for a tram system than for bus. The environmental impact of a tramway in Bathampton village would be significant. It may be feasible to use part of this route as an alternative alignment to serve the Lambridge Park and Ride site but substantial structural engineering works would be needed to cross the canal, railway and river in an environmentally sensitive area.
Larkhall and Batheaston
3.33 The Batheaston route leaves the City Centre circle along Walcot Street and continues along London Road, A4. It is proposed to locate single track with passing places in the centre of London Road. This would require all other traffic to be confined to a single lane in each direction. While there is adequate width over most of the route, the impact on traffic movements would be substantial. There are many frontage properties which appear to have no rear servicing facilities, and it may be difficult to provide satisfactory alternative arrangements.
3.34 London Road is heavily congested and the Cleveland Place junction is particularly difficult with no scope for improvement. Traffic is severely constrained by adjacent listed buildings. Some bus lanes have been provided along London Road and more are planned but these could not easily be adapted to serve the tramway as proposed. TfB have suggested a road layout and traffic signal arrangement which would afford priority to trams.
3.35 The Larkhall route diverges at St Saviours Road for about km to terminate at Larkhall Square. This offers only limited access to the Larkhall and Fairfield areas compared to the existing bus services, which circulate around both residential areas.
3.36 The Batheaston TfB route continues along London Road and crosses the Batheaston by-pass where it may be feasible to provide some limited roadside reservation. Through Batheaston village the road is narrow and there is no scope for segregation. Batheaston and Bathford are relatively low-density high car ownership areas and it may be difficult to attract sufficient demand to justify a fixed track system.
3.37 The proposed Park and Ride site at Lambridge could be served by this route, and it could be linked to the Newbridge route to improve access through the City Centre and provide access from the east to the Western Riverside development. While demand further east may be low, a route to Lambridge could be attractive. Its success would depend on managing traffic to ensure reliable operation and this may be difficult to achieve. Alternative off-highway alignments as proposed in previous studies would be preferable from a transport point of view, but there may be environmental difficulties and effects on Listed buildings with these off-highway alignments.
Lansdown Park and Ride
3.38 The Lansdowne route leaves the City Centre circle at Northgate Street, the same location as the Batheaston route, but then uses Broad Street to reach Lansdowne Road. The route climbs over 150m in about 3km with some sections of gradient between 10% and 12%. A roadside reservation could be achieved over some parts of the route if parking was removed and the northern section has a grass verge, which could be used as a reservation. Some lower sections including Broad Street and very narrow and with no scope for segregation. Double track would be needed and some traffic management measures may be necessary.
3.39 The gradients would impose significant constraints and would make this route more difficult to implement. Although it is sated that trams did previously operate on a 12% gradient on Broad Street this was only over a short section and only in an uphill direction. Operating in both directions over some 3 km of continuous gradient would be considerably more demanding.
The City Centre Circle
3.40 It is proposed by TfB to create a one way circular route around the City Centre from the rail station as described in Para.2.2. All trams would terminate in the City Centre by traversing the circle and returning to their entry point for the outward journey. This would offer good central area distribution but would create a very high tram flow if all routes were built; equivalent to a tram about every 30 seconds. Furthermore, any delay at any point on the circle would immediately affect every service and would create severe operational difficulties.
3.41 The form of the City Centre street pattern and the narrow width of many streets would make the provision of an all double- track system difficult to achieve and therefore a single-track layout has some benefits. The optimum layout for the City Centre would depend on which routes were to be linked. A key objective for any route structure would be the need to serve the rail and bus stations. If for example the east-west routes were to be constructed, linking Newbridge with Lambridge, then a route using the southern part of the proposed circle would be the most effective but this would require a two way track over this section. Alternatively, parallel one way tracks could be considered using the two routes suggested (St James's Street and Avon Street) or short sections of single track for two way operation may be feasible.
The most difficult part of the City Centre circle would be Upper Borough Walls, which is very narrow, and where there are conflicting requirements with local access traffic including to the hospital. A route in the form outlined above would not need to use this section, which could possibly be considered as a later stage to any central area system.
Traffic Management
3.43 The TfB proposals apparently envisage a primarily single-track system with passing places and running mainly within the existing highway. Very few references are included to indicate the traffic management measures necessary to provide for the safe movement of trams with heavy traffic flows and pedestrian and cycle movements. The form and location of stops is also not shown.
3.44 In some route sections it may be feasible to provide reserved track at the side or in the centre of the carriageway but many of the roads are only 7m or 8m wide. A minimum of 10m would be needed to provide any form of reserved track. There are major issues regarding safety that would need to be addressed if trams were to operate in both directions on the same track within existing traffic lanes. It is unlikely that any form of single-track operation within the carriageway would be acceptable to HMRI (Her Majesty's Railway Inspectorate). Single-track operation within the highway may be feasible if adequate methods of segregation could be devised.
3.45 Where passing loops were provided, the transition from single track to double track, and vice versa, would need to take full account of all conflicting movements by other road users. Appropriate traffic management measures would have to be included to ensure safety. In many cases this may require provision of additional traffic signals. Where stops were provided, whether in passing loops or on single track, the location of platforms in relation to other traffic movements, and also to footways and pedestrian crossing facilities, would need careful consideration.
There are a number of major intersections on the proposed network, which are already overloaded at peak periods. They include Churchill Bridge junctions and gyratory and the Cleveland Place/London Road junction. There are no proposals made for traffic management measures or any indication of how a single-track system could operate through these areas. In practice double track would probably have to be used and this could extend over considerable lengths of route with obvious consequences for cost estimates.
Rolling Stock
3.47 The type of rolling stock suggested by TfB has the following characteristics:
Each of these factors is briefly considered in the context of the proposed network for Bath.
3.48 Double-ended vehicles would avoid the need to provide turning circles at termini and intermediate turnbacks and make depot manoeuvring more flexible. The are a number of proposed termini where it would be very difficult and/or expensive to provide turning circles. The use of double-ended vehicles would probably be the most cost-effective option. However, single ended vehicles would be cheaper to purchase, as they only require one cab and are likely to be cheaper to operate as no time is required for drivers to change ends. A comparative analysis of options should be undertaken at a more detailed planning stage.
3.49 It is normal for double ended vehicles to be double sided (i.e. have doors on both sides) and single ended vehicles to be single sided. Double-sided vehicles allow more flexible location of platforms as they can be on the nearside or offside (side platform of island platform) whereas single sided vehicles can only use nearside platforms. However single sided vehicles are slightly cheaper to purchase and maintain because they have half the number of doors and have a higher capacity for a given vehicle floor area. The analysis of vehicle options should include the options of single or double-sided trams.
3.50 Double decked trams are unlikely to be cost effective and it would not be desirable to have two different vehicle types in a relatively small fleet. There are a large number of new light rail systems that have been built in the past twenty years and none have adopted double deck vehicles. As far as is known, only one system considered double deckers as an option (Tuen Mun in Hong Kong) and they were rejected. There is a wide range of low floor single-deck designs available on the market but no double deck designs. If it was decided to operate some historic tourist vehicles, then double deck trams could be considered, either original restored trams or more probably newly built replica vehicles, as for example operating in Birkenhead using Hong Kong double deck trams.
3.51 Capacity of 150, with about 50 seated + 100 standing is a typical figure for a modern small light rail vehicle (LRV). For example, the Midland Metro LRVs operating between Birmingham and Wolverhampton have a capacity of 158 with 56 seated and 102 standing. This would be an appropriate capacity for planning purposes, which could be refined as more detailed demand figures became available.
3.52 Low floor will be an essential feature of any new tram design to comply with the Disability Discrimination Act provisions and the requirements of HMRI (Her Majesty's Railway Inspectorate). Level boarding would be required at all stops with a minimal gap between platform and car floor. While this could be achieved with a high floor design, as in Manchester, the need for high platforms in the street would be physically and environmentally intrusive and could not be accommodated at many stop locations on the proposed network.
3.53 Weight around 15 tonnes would be difficult to achieve with any existing LRV design. Most current LRVs of the overall type envisaged would be in the range 25 to 35 tonnes. Some new designs claim to be able reduce overall weight substantially but it is unlikely that a vehicle weight much less than 20 tonnes would be achieved.
3.54 Twin-bogies is one possible configuration although a more typical arrangement would be for a two section single articulated vehicle on 6 axles. However there is now a wide range of low floor vehicle layouts available including some modular designs, which permit considerable flexibility. It is not necessary at this stage to specify any particular configuration.
3.55 Standard gauge track is normally adopted for any new light rail or tram system. It permits the greatest flexibility in use and supply of components for vehicles and track, as there is a wide range of equipment readily available. The only alternative would be metre gauge track, which is used extensively on European systems, particularly for tram systems in smaller and historic cities. It can be considered less intrusive and more in scale with narrow city streets. However, virtually all new light rail systems have been built to standard gauge, including all those in the UK.
3.56 550/750 volt DC electrical supply by overhead wire is the normal method of power supply for tramway and light rail systems. For new systems, 750 volt DC is now effectively the standard voltage and would be the appropriate choice for Bath. A lower voltage of about 600 vDC would be appropriate for a historic tramway, using original restored rolling stock but this would not be the mainstream function of any tramway for Bath. Replica vehicles could be designed for 750 vDC operation. It should be noted that overhead power supply can be designed to be relatively unobtrusive, as can be seen in photographs of the original Bath tramways. Alternative power sources that do not require overhead line equipment could be considered such as diesel, gas engine (e.g. LNG), or stored energy using flywheel technology as developed by Parry People Movers.
3.57 Motor power around 15kW per tonne, all axles driven is probably typical of the power requirement for a tram system in Bath. Actual figures vary considerably between different LRV configurations and specifications. It would not be necessary at this stage to specify the power output but it would be essential to have all axles motored to negotiate the gradients found on a number of proposed routes in Bath. This requirement would limit the number of designs that would be appropriate.
3.58 Combined regenerative, frictional and magnetic braking is the standard combination of braking systems on most modern LRVs. Electromagnetic track brakes are a standard requirement for any street running light rail vehicles. The precise form of braking systems for Bath would need to be considered at the detailed specification stage and would need to incorporate adequate safety features for operation on gradients up to 12% which is about the limit for an adhesion railway. The HMRI would need to be consulted with the proposed system for use in Bath. TfB made initial contact with HMRI in 1999.
3.59 The rolling stock specification would need to be developed as the project proceeded. A number of options are available or may become available which could be considered in due course. Some examples are given as illustrations.
3.60 A number of manufacturers are now offering modular designs, for example the Siemens Combino and the Alstom Citadis, which are low floor vehicles that can be produced in a range of layouts. They use standard body sections, cab ends, articulation units and traction units to create differing vehicle lengths, widths, door arrangements, internal layouts and power requirements.
3.61 Two British developments which could have potential for a system in Bath are the 'TRAM' vehicle currently under development at Blackpool and the Parry People Mover currently in trial operation in Bristol and proposed for operation in a number of medium sized towns including Stourbridge, Weymouth and Llandudno. Both these projects are some way from full commercial exploitation and may not be able to meet a specification for Bath when that has been developed. They would have to bid alongside more conventional vehicle designs for any contract to provide rolling stock for a Bath tramway. TfB have pointed out that the Parry vehicle is unlikely to be suitable for the hills in Bath, but they may be suited for the more gently graded Lambridge to Newbridge route.
3.62 Rail based options should be compared with bus based options, either guided bus or manually steered bus, for the routes or networks to be considered. It should be noted that any rail based option would need to be tracked throughout while a guided bus system could only be tracked on those sections of route on separate right of way or where there were no other traffic movements along the tracked section.
System Costs
Capital Costs
3.63 The total capital costs have been estimated by TfB at £71 million, made up as follows:
| £m | |
| Track | 24 |
| Vehicles | 25 |
| Electrical and signals | 15 |
| Depot | 4 |
| Diversion of services | 1 |
| Works | 1 |
| Stops and equipment | 1 |
| Total | 71 |
3.64 The track cost equates to £625,000 per track km. It assumes use of the LR55 rail, which has not yet been produced in rolled steel. This cost also assumes mainly single track with passing places but the number and location of passing loops and associated pointwork is not given. This could significantly increase the total cost.
3.65 The vehicle cost is based on a figure of £500,000 per vehicle as originally indicated by the TRAM Group for the Pullman type vehicle. A total of 40 vehicles are proposed giving a total cost of £20 million which has been increased to £25 million to allow for contingencies. A typical cost for a light rail vehicle is about £1.3 million and more recent estimates for the Pullman vehicle suggest a figure closer to £1 million may be more realistic.
3.66 The number of vehicles needed to operate the service on the network has been incorrectly estimated because no allowance has been made foe the sections of route which are shared by more than one service. If all routes operated at a 6 minute headway then a total of 65 trams would be needed. This would reduce to 55 trams for a 7 minute headway, 42 trams for a 10 minute headway and 31 trams for a 15 minute headway. TfB suggest 6 or 7 minute headways but if a 10 minute headway is assumed, then the number of trams would be 42 plus engineering spares, say 46 in total. If it is further assumed that low cost vehicles could be obtained at a price of say £1.1 million, then the total cost of vehicles would increase to £51 million. It should be noted that the Pullman vehicle on which the TfB cost is based does not have all axles motored as required for the gradients on the Bath system. The cost is likely to be higher to reflect the higher specification.
3.67 Electrical power supply and signalling costs are estimated at £15 million. It is assumed that the system would be 'drive on sight' as for most tramways and the only signalling would be in respect of tramway aspects on traffic signals and for safety signalling on single-track sections. Given the extensive use of single-track proposed, the signalling costs could be significant although no specific figures are given.
3.68 The cost of the depot is given as £4 million. This is likely to be low given the need to provide full maintenance facilities for a fleet of about 45 vehicles. A wheel lathe, probably costing over £1m, would be essential given the likely level of wheel wear that could be expected on the system. A more realistic depot cost may be between £8m and £10m.
3.69 It has been assumed that use of LR55 rail will reduce or eliminate the need for service diversions in most cases although this has yet to be fully demonstrated. The cost for diversion of services is therefore given as only £1 million. It is further argued that it is not necessary to relocate all services as normally required for a 'heavy' light rail system. Service diversion costs are typically in the order of £2 million per km, which if applied to Bath would give a total cost of around £72 million. A realistic figure somewhere between these extremes may be in the order of £20 million.
3.70 An allowance of £1 million has been
made for other works including bridges and other road works. Associated
works for a tramway can be substantial including, for example,
regrading carriageways to accommodate horizontal and vertical
curves of the track, minor highway and traffic management improvements
and 'off-line' improvements to accommodate diverted traffic movements
such as essential servicing access. A figure of £5m may
be more realistic.
3.71 A cost of £1 million has been included for stops and
equipment, equivalent to about £12,500 per stop assuming
a total of 80 stops. Given that many stops would require a platform
in each direction, as stops would normally expected to be sited
on passing loops where possible, the total number of platforms
to be provided could be up to 160. Although a tram platform may
be very simple, it would now have to comply with regulations regarding
accessibility including the provision of level access and tactile
paving. This is likely to cost significantly more than allowed
for in the estimate.
3.72 The effect of these changes would increase the total capital cost from £71m to at least £125m. This figure is still extremely low by light rail standards being equivalent to just over £3m per route km compared with over £6m per km for the cheapest street running systems built in recent years. While a simple street tramway would be expected to cost less than a full specification light rail system, it would seem that the figures adopted by TfB are optimistic.
3.73 Some revised cost estimates have been prepared taking account of all the factors discussed above. Estimates have been made for the whole network as defined by TfB and also for a 'first phase' line between Newbridge and Lambridge assuming a total route length of about 10 km. The figures for the first phase line are proportionately higher than for the whole system because of the high civil engineering content of this alignment and also because of the economies of scale that may be expected with a larger system. The resulting outline costs are shown below for illustrative purposes only. It would be feasible to provide vehicles, which did not require overhead electrification, for example diesel or gas powered trams or stored energy as used by the Parry People Mover. Costs would be reduced as indicated by the figures in brackets.
Potential Capital Costs for a Tram System for Bath
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Estimate |
£m |
Newbridge - Lambridge £m |
| Track |
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| Vehicles |
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| Electrical and Signals |
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| Depot |
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| Diversion of services |
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| Works |
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| Stops and equipment |
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| Total |
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On the Newbridge to Lambridge corridor, the cost of either on-street or off-street alignments are probably similar. Service diversions and traffic management costs for the former would be of the same order as earthworks and environmental costs for the latter. The above figures include detail design costs.
The cost of public enquiry preparation cannot be estimated without a detailed programme. However, at a recent TW& A inquiry into a mass transit scheme at Liverpool, a range of £750K to £1m was quoted by Merseyside Passenger Transport Executive as the cost of the immediate preparation for the inquiry.
The level of operating costs is dependent on the ultimate form of service pattern, vehicle type, safety requirements, maintenance regime and other aspects of system specification.
At this stage it is therefore only possible to consider overall capital cost estimates for outline appraisal purposes.
Demand/Revenue
Estimates made by TfB assume a large transfer of patronage from bus. Given the deregulated environment, which currently applies, and the greater extent of the bus network compared with the tram network, this assumption may be too optimistic.
A detailed study of potential patronage from all sources including transfer from bus, car, walk or cycle and generated traffic is required, together with a range of sensitivity tests.
For the purposes of the current review, for illustrative purposes an alternative -demand estimate of potential future network demand is provided below, together with a comparison with TfB figures;
Alternative Patronage Demand Estimate
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Trips |
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| Car |
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Given the cost of the system and the need to maximise revenue an ultra low fares policy is not probable. |
| Bus |
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It would be difficult to exceed this degree of capture on a network basis. |
| Park and Ride |
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This assumes that current policies lead to Park and Ride provision being doubled. |
| Generated Trips |
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This reflects the effect of a new system in attracting an assumed 10% of additional new trips. |
| Daily Total |
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Review Estimate |
| TfB Total (Low) |
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http:/bathtram.demon.co.uk/Website1/tF22.htm |
| TfB Total (High) |
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http:/bathtram.demon.co.uk/Website1/tF22.htm |
| Weekly Total |
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Review Estimate (x6) |
The above figures indicate that the TfB upper range patronage estimate appears to be over optimistic. Taking the running costs quoted by TfB, we have assumed that the operating costs could vary between £96,052 to £192,103 per week, dependant on the type of system specified, [i.e. either guided bus/PPM or light rail respectively ñ see also 1995 Pre-Feasibility Report ñ Table 7.8]. Then taking the likely revenue as a constant, with the operating costs being treated as variable, the minimum break even average single journey fares (i.e. running cost divided by number of journeys) are as follows; Low Fare £0.74 High Fare £1.49. Whilst this does not allow for the likelihood that light rail may have a relatively higher patronage potential, it does indicate that light rail may only be feasible on the best performing routes with bus based technology the best option on secondary corridors.
It would be possible to undertake definitive tests of alternative networks and individual corridor rapid transit proposals through a further more detailed assessment of potential patronage and revenues. This could be a free-standing study utilising available data and models where appropriate.
3.83 Procedures
The 1998 JMP report stated ''All rail-based
transit system require
authorisation in the form of an Order made under the Transport
and Works Act 1992 - a lengthy procedure involving provision for
a Public Inquiry if objections are received. Bus-based transit
systems only require a similar Order if electric power is derived
from an external source or if a guided bus system is proposed
extending beyond existing highway limits''.
On the basis of the current review it appears likely that a T&WA Order will be required and the time-scale for implementation needs to take account of this. For example, two years to Order publication - in which time a series of studies need to be undertaken to demonstrate the viability, feasibility, impact and value of the scheme in overall appraisal terms.
It would be advisable to prepare a list of required studies and consultation exercises as soon as possible and to take advice from experienced Counsel on the structure of the outline programme. This is highly recommended, as early preparation for Inquiry when a complete case needs to be presented, will give the best chance of success.
Equally importantly is the process of procurement and funding the scheme, in whatever form it emerges. Essential components of this are the choice of operator, private sector financial contributions and Goverment grant support. For this, a variety of tendering and assessment procedures need to be followed, and each is time-consuming and needs careful preparation.
A formal grant application would only be submitted after the system was approved, but all the assessment work needs to be completed in advance and discussed informally with the DETR.
To complete the above programme inside a two-year programme is tight but may be achievable given the background studies and models already completed.
3.84 Demand/Operating Costs/ Revenue/Viability
The 1995 JMP report compared the operating costs of guided bus and light rail alternatives [see Table 7.8 in that document]. This showed that the costs of a conventional light rail system would be approximately double that of guided bus, whilst an ultra light rail alternative, the Parry People Mover, would be very similar in cost terms to guided bus.
Looking at the TfB cost and revenue information, this provides a range of possible operating costs for initial assessment purposes - see replacement section for the report on demand/viability attached.
Appraisal
Qualitative Assessment Table, for the TfB Proposed Network, Based on Initial NATA Type Appraisal Criteria
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Sub-Category |
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| Beneficial | Neutral | Adverse | ||
| INTEGRATION | ||||
| Interchange | Substantial | |||
| Mode Shift | Substantial | |||
| SAFETY |
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| ECONOMY | ||||
| Employment | Moderate | |||
| Regeneration | Moderate | |||
| Time Savings | Moderate | |||
| Operating Costs |
Moderate |
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| ACCESSIBILITY | ||||
| Public Transport Users |
Substantial | |||
| Mobility Impaired | Moderate | |||
| Car Users | Substantial | |||
| ENVIRONMENT | ||||
| Noise | Slight | |||
| Air Quality | Moderate | |||
| Biodiversity | Moderate | |||
| Heritage | Slight | |||
| Water | Yes | |||
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