03What public transport tells us about levelling up
Increasing public transport accessibility and, therefore, commuting is important for several reasons, and has both environmental and social benefits. But in the context of levelling up, improving the economic performance of big cities outside London should be the priority for public transport policy as their unfulfilled potential damages the national economy and widens regional inequality.
Returning to Figure 1, which indicates that big cities in Britain underperform given their population, and adapting it to include their effective size (determined by the number of people who can potentially reach the city centre in 30 minutes), helps to explain this underperformance. It also shows that the effective size of big cities is much smaller than their actual size.
Figure 14 indicates that the relationship between productivity and effective size (in dark green) is stronger than the link with population (light green) when looking at British and European cities. This is primarily driven by the marked difference, in Britain, between population size and effective size due to poor public transport accessibility.
Figure 14: Manchester’s poor public transport accessibility reduces the size of its labour market, and helps explain its economic underperformance
For example, Manchester’s population is similar to Rome’s, but the Italian capital is 55 per cent more productive. This is partly due to its larger effective size, as many more commuters can travel by public transport into the city centre. Manchester’s effective size is closer to that of Dortmund, which has a far smaller population and narrower productivity gap of 12 per cent.
Improving public transport networks in big cities will help to close their productivity gaps
A simple estimate shows that raising the effective size of big cities to European levels would increase agglomeration benefits to the tune of £23.1 billion each year.16 Table 1 indicates, by looking at the distance between big British cities and the light green trendline in Figure 14, that poor public transport accessibility – caused by a low-rise built form in every city and small networks in some – is limiting the effective size of large cities and damaging their economies. This simple estimate is shown visually in Appendix 3.
Table 1: Mobility helps explain the productivity gap in some cities
|PUA||Productivity gap, due to weak public transport accessibility (£ million)|
It is important to note, however, that while achieving deeper agglomeration effects in large cities outside London is essential for levelling up, public transport accessibility alone is not enough to explain the gap because cities face other barriers too, such as inadequate skills.17 18
Together, Manchester, Birmingham and Leeds account for around two thirds of the estimated gap that arises in big cities from poor public transport accessibility. Manchester alone accounts for 38 per cent and it is here that it appears to have the greatest impact on productivity. A simple estimate suggests that boosting the city’s effective size from around 490,000 to 1.3 million people could improve productivity by 15 per cent. In contrast, the problem in Glasgow is far less immediate. Policy should look to improve public transport further to increase the pool of workers available to businesses in Manchester, but developing skills is a much higher priority challenge.
Big cities need to enable more people to live in areas with good public transport connections to improve accessibility and encourage use. This, however, depends on increasing the density of their urban form – a London-style transport system requires London-style density. While this may put pressure on infrastructure in the short term, in the long run it would increase demand permanently. More guaranteed passengers would lock in more frequent, cheaper and better public transport, and improve the business case for further investment.