Analysis of the forecast impact of Tif Manchester

The two projections from pages 241 and 242 of the submission (Part 7), aiming to show the impact of the extra investments in public transport, along with the congestion charge. These I have combined to show the total changes projected, along with the total of public and private transport.

Figure 71 – Reference case:Difference in people Crossing the inner ring (2005 to 2016) p.241
Highway Bus Rail Metro-link Total Pt TOTAL Highway + Pt
Entering Regional centre 2,300 -1,300 1,300 4,000 4,000 6,300
Crossing Inner Charging Ring 8,400 -1,700 1,400 4,000 3,700 12,100
Figure 72 – TIF Package:Difference in people Crossing the inner ring (2005 to 2016) p.242
Highway Bus Rail Metro-link Total Pt TOTAL Highway + Pt
Entering Regional centre -3,300 5,800 2,100 2,400 10,300 7,000
Crossing Inner Charging Ring -6,400 7,200 2,300 2,800 12,300 5,900
Total Differences between people Crossing the rings if Tif Implemented (2005 to 2016)
Highway Bus Rail Metro-link Total Pt TOTAL Highway + Pt
Entering Regional centre -1,000 4,500 3,400 6,400 14,300 13,300
Crossing Inner Charging Ring 2,000 5,500 3,700 6,800 16,000 18,000

There are a number of comments to be made.


  1. Total travellers at peak time compared to employment growth.


Claims have been made that the difference in jobs will be 30,000 between the measures being enacted and not. With the measures, the region gets an extra 200,000 jobs, without 170,000.

Only a small proportion of these jobs will result in peak time travellers entering the regional centre, or crossing the inner charging ring, but the ratios should be similar. They are not.

The impact of the Tif Manchester on jobs and peak-time travellers
170,000 Jobs Extra 30,000 Jobs
Travellers Jobs / Traveller Travellers Jobs / Traveller
Entering Regional centre 6300 27.0 7000 4.3
Crossing Inner Charging Ring 12100 14.0 5900 5.1

Without Tif, the 170,000 extra jobs lead to only 6300 extra people entering the regional centre and 12100 crossing the inner charging ring. If these numbers all stack up, then it shows allowing congestion to increase would cause the new workers to locate close to their jobs, whilst improving transport will encourage people to live in the suburbs. But the differences are so huge, they can only mean that the extra travellers estimate is in no way related to the extra jobs. The figures do not stack up.

  1. Metrolink impact.


The impact of doubling carriages on the Altrinham/Bury line and added a spur to Trafford Park will increase peak passenger numbers by 4000. Adding a lines to East Didsbury and Rochdale/Oldham will add around 2400 to 2800 more. Clearly £1.2bn is not good value at peak times. Further, it puts the East Didsbury line in doubt. Between the regional centre boundary and the inner ring boundary, only a net 400 extra passengers are picked up. That is about 200 people from Chorlton and Didsbury areas using the Metrolink to travel into Manchester at peak times.

I believe the figures will be much greater. It is the model that is wrong. It is possibly the shift to the buses that is overstated.

Financially we have a problem. If you take out the cost of the congestion scheme, only 23% of the peak time growth in passengers on public transport will be on new Metrolink, but around half the cost.


  1. Buses


The buses are crucial to the whole plan, with over 55% of the growth in those travelling on public transport at peak times from the Tif Manchester using this mode of transport. The switch from cars will be mostly use Yet, as I blogged on 30th Sept (Flaw 2), there are good reasons to believe that people will continue to use the car over the bus. Those are

i)                  Cars are much quicker, and more reliable than buses. So even with if the average traffic speeds increase, people will spend much longer travelling by bus than they had previously done so by car.

ii)                With the congestion charge, traffic speeds at peak times are forecast to improve by 33%, but average bus journey times by just 12%. For those who can afford the congestion charge, the advantage of car over bus increases with the charge.

iii)             Many people will be able to afford the maximum £1200 congestion charge by keeping their cars for longer, or by switching to cheaper cars. The proposed fees are much too low.

iv)              The congestion charge is only impact on less than 20% of drivers. Even allowing for those who switch from cars to public transport, it is still a minority of car drivers. The congestion charge is not extensive enough, both is times, or in reach.


  1. Seasonal factors.


A further way that travelers can reduce the cost to them of the congestion charge is to use public transport in the summer, when the weather is pleasant, and to use their cars in the colder winter days, especially when travelling in the dark on the short days. That is when the benefits of travelling by car are the greatest it is more worthwhile to pay the premium. With a relatively low level of charge, this may be a pattern that emerges. It would mean there may be gridlock that can occur Christmas Eve would extend to other cold periods. This could also mean that not only would there be peak time public transport issues, but also seasonal ones as well.


Conclusion and implications


The numbers do not add up, nor do they correspond to other data on employment. The increase in volumes of travelers is not related to projected growth in the jobs; the impact of the new metrolink lines is understated for crossing the inner rings, and the switch from cars to buses is not simply not credible for the level and the extent of the charge.

The model and forecasts do not add up. I would strongly recommend that an independent auditor or economist checks the model and the results to see if the figures are credible, and to assess the risks.


How the projections can go wrong.


As an economics graduate and with over twenty years of management accounting experience, I can understand how the figures do not stack up.

1)    In compiling a model of human behaviour a number of simplifying assumptions and generalizations have to be made. With a complex issue like transport in a city over two million people, these are considerable. Using a simplified model based on existing structures to then look at the implications of a major structural change is fraught with dangers.

2)    There is little data on congestion charges so far, and the proposed Manchester charge will easily be the biggest charge area in the world. Therefore we can only draw tentative inferences from the few other examples. With a requirement to include congestion charging, it could be that there is an in-built bias towards the effectiveness of such schemes.

3)    When compiling a forecast with disparate elements, then totality of all the trends must form a credible picture. This will often mean adjustments to bring the factors into line. This has probably not occurred.

4)    In compiling the congestion charge model, political acceptability of the proposed charging structure may have overrode previous “optimal” charges. It could be that the forecast shifts from road use to public transport were based upon a more stringent congestion charging regime.



Comments are closed.
%d bloggers like this: