It's not just the faces of the leading contenders that are familiar in this London mayoral election, but many of the big policy battles as well.

Last time around, in 2008, Boris Johnson stood on a platform of cutting waste and using the money to build a "new fleet of Routemaster buses". His opponent Ken Livingstone bitterly opposed him, saying that the cost of re-introducing conductors would be £100m a year alone. Johnson countered with much lower calculations, and commentators, academics, and transport officials all excitedly joined in the fight.

As an increasingly bored electorate looked on, the combatants became locked in a fantastically nerdy debate about hybrid engines, conductor shifts and bus tendering arrangements.

Fast-forward four years, and Johnson is once again standing on a platform of introducing a new fleet of Routemaster-style buses and Livingstone is once again standing on a platform of opposing him.

The battle began earlier this year as Transport for London (TfL) took a working prototype of the bus on a pre-election tour of suburban high streets. As the bus crawled from place to place, another bus filled with campaigners against Johnson's re-election followed in convoy. Meanwhile Johnson himself took to the wheel, making this possibly the first time that an election candidate has charged the cost of his campaign bus to the taxpayer. Livingstone has now also joined in the battle, telling the Guardian he will scrap any further production of the buses if he is re-elected.

For ordinary commuters stuck in overcrowded buses on overcrowded streets, this must seem like the most pointless and self-indulgent of debates. The original bendy buses were certainly disliked by some motorists, but appreciated by many of the people who actually used them. Their replacements meanwhile are expensive, do not solve the problem of fare evasion and require an extra member of staff whose only job appears to be to stop people falling off the back.

But despite this the reaction on the streets to them has been broadly positive. Whether it's nostalgia for a London that's gone, or genuine admiration for their design, the new buses are proving popular even among those who initially opposed them.

Because the truth is that unlike Livingstone and Johnson, most Londoners do not see bus design as a major political issue any more than they do taxi design or train design. The new fleet, if finally built, will be popular among some people and seen as impractical among others. But when compared with the big issues of congestion, air quality and affordability, the question of bus shapes is of almost no significance to most Londoners.

When TfL asked people what the top priority should be for the bus network, the most popular suggestion was to provide "more information at bus stops". "Developing a new bus" barely registered. But then improving bus timetables is never going to be as sexy for a mayoral candidate as the opportunity to climb aboard your own custom-designed bus.

Meanwhile the real world carries on, and unlike the country as a whole, unemployment is still increasing in London. Widening inequality, polluted air and violent crime are still all big issues in the capital. Unfortunately none of these are likely to get a look in, while both the major candidates are still obsessing over each other's tax returns and bus designs.

In this most personality-based election, where the job itself has few real powers, it is probably inevitable that the debate gets bogged down in trivia. But for the same trivial issue to be a major battleground two elections in a row may finally stretch the patience of Londoners too far.

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