Surveying the state of our highway bridges

The telling thing about this year's now annual RAC Foundation survey of the state of highway bridges is not the headline total of those not able to carry the heaviest vehicles on Britain's roads but the gap between how many of them highways chiefs want to bring up to scratch and the number which, on current form, they can afford to strengthen.

Between them, the 199 councils in England, Scotland and Wales who responded to our requests for information manage 71,656 structures over 1.5 metres in span. Of these 3,105 are so-called 'substandard' meaning they aren't up to being used by some of the bigger lorries now seen on our roads.

In many cases – this isn't a problem. A bridge tucked away down a country lane in one of our larger and more rural counties is unlikely to be troubled by articulated lorries and anyway, a well-placed sign indicating a weight limit will deter those vehicles likely to put it under undue strain (so long as the satnav guiding the driver has the right, up-to-date routing information).

Yet in other cases it can be a problem. Council bosses have identified 2,256 bridges – 73% of the substandard total – that they would ideally want to improve. Unfortunately, they believe only 392 of these will have the necessary work carried out within the next five years, the main limitation being budgetary pressures. That's less than 18% of the total and assumes the financial squeeze likely to follow the cost of responding to coronavirus doesn't trim their ambitions back still further.

Even that is not the whole story - there is reason to believe another serious problem is lurking out of sight which will only increase the number of structures not up to the job: the damage being caused by the scouring effects of rivers on bridge supports and the battering they are taking from the debris the water is carrying.

In an era where the incidence and severity of flooding seem to be rising as a result of extreme weather events, one would hope that the inspections and assessments of vulnerable structures would be growing in tandem. Instead, it appears to be shrinking.

Again, money is an issue, in this case the resource – running cost – spend which, if anything, is more stretched than the capital budget. But so too is the expertise needed to monitor the condition of these vital structures, and in the past twelve months Covid hasn't helped. These assessments are not academic, box-ticking exercises. They are crucial to ensuring the integrity of the bridges and the resilience of the transport network they are part of. Several councils reported to us that they had suffered partial bridge collapses. Four reported total bridge collapses.

While potholes are the ubiquitous symbol of stressed road maintenance budgets it is arguably our fragile bridges that should be the more worrying canary in the coalmine.

Another RAC Foundation study hints at further emerging strain on council budgets. We reported at the start of this year that English councils had made a combined surplus – profit if you like – of £891 million from their on- and off-street parking activities (before servicing debt accumulated to create parking facilities – incredibly hard to discern from the MHCLG data). This was down £43 million on the previous 12 months, and the total for the current Covid-stricken financial year, in which traffic volumes have dropped dramatically as people follow orders and stay away from the High Street, is likely to fall still further.

We have long reminded councils that parking charges can't be treated as a general revenue raiser - the law is clear on that; parking restrictions, fees and penalties are there to manage traffic, not to become another tax on motorists. Nevertheless, the restriction on spending the proceeds allows transport and environment-related projects to be funded, and if those 'profits' fall the ensuing squeeze is likely to hurt.

Whether we think that private car use must be reined back to achieve our climate goals, motor traffic restricted to improve our air quality, or simply that we all should be willing to travel less as we head towards our net-zero carbon future, our road system will surely continue to be as much a vital utility as our power, water and telecoms networks connecting to our homes and workplaces, and so we think its health should be a primary concern for national and local government.

If we think of our roads as simply being there for cars we risk missing the fact that they are there for walking, cycling, buses and deliveries. If we focus, as is always the temptation, on new investment we risk missing the need to maintain what we have.

It might not offer us the glamour of a ribbon cutting ceremony but bolstering capital and current investment in the maintenance of our roads – including the bridges that carry them - is surely key to our economically successful and sustainable future.