When Barbara Castle, a non-driver, was appointed Labour’s transport secretary by Harold Wilson in late 1965, she was subjected to a predictable barrage of male media questioning about her fitness for the job. One in particular, a Poundshop Jeremy Clarkson before his time, disparaged her plans to test motorists for their alcohol consumption on the BBC’s The World This Weekend.

‘You’re only a woman, you don’t drive — what do you know about it?’ I reckon I can take five pints and drive better than most people any day of the week,’ he said. ‘Yes, I know,’ replied Castle, in the manner of a genteel nurse about to rip off a plaster. ‘Famous last words.’

To an earlier generation of Tribune readers, the reputation of Barbara Castle as a leading — and principled — figurehead of the post-war left was damaged irreparably by her stint as Wilson’s employment secretary at the end of the 1960s. Her 1969 White Paper, In Place of Strife, sought to subdue trade unions just at the point where workers had begun to claim major victories without the aid of Wilson’s corporatist fudging. It didn’t work, succeeding only in winding up Labour’s allies while anticipating the later evisceration of union power after 1979; only the Equal Pay Act, pushed through by Castle before the Tories regained power in 1970, redeemed her.

But Castle commenced her political career as an unequivocal leftist, writing for Tribune from its founding issue in 1937 and forming part of what became Labour’s Bevanite — or Tribunite — bloc after her election as MP for Blackburn in 1945. Having fought tenaciously for Labour to govern from the left during its thirteen years of opposition from 1951, she was promoted rapidly once Wilson formed a minority government in 1964.

After two years as international development secretary, Castle took transport — an unloved and unsexy government brief — and turned it into a living vindication of Labour’s purpose and ability in power. Both civil servants and her Tory predecessors thought the only thing left to do with transport was to complete the road network. She saw her task as taking the country’s ramshackle — though still extensively nationalised — transport infrastructure and turning it into a fully integrated, socially-useful system fit for both everyday mobility and Wilson’s much-heralded ‘technological revolution’.

Transport brought out in Castle what her contemporary Roy Jenkins described as ‘a certain obsessiveness about issues’. For her, those issues encompassed road passenger and pedestrian safety, the quality of everyday working-class life, the constant improvement of the public realm through planning, and the rescue of the railway network from the threat of near-extinction following savage cuts in the early 1960s.

She told Labour conference in 1966: ‘We must plan transport now as an integral part of all our other planning — our planning for national expansion, our planning for regional development, our planning to protect and improve our environment.’ In some respects this was straightforward, given the extent of state ownership of transport infrastructure at that time.

The rail network, both passenger and freight, had been nationalised in 1948 along with road haulage (including, incredibly, parcel delivery services and the removals company Pickfords). Buses were run as a municipal service and were still by far the most commonly-used form of transport, though private cars were beginning to catch up in terms of passenger mileage. To Castle, integrated transport meant planning for public transport to work properly and for its users to travel in comfort.

Yet it was impossible for a transport minister in the late 1960s to ignore the increasing dominance of the car. It was widely believed that, given the apparently irreversible trend towards private transport, central government should focus funds and attention on reducing congestion and pollution, rather than maintaining public transport as a viable alternative. A landmark 1963 report, Traffic in Towns, produced for the government by the planner Colin Buchanan, had recommended the drastic reshaping of urban road networks so as to keep pedestrian and car traffic totally separate.

In response, cities such as Birmingham, Liverpool, and Glasgow planned, and in many cases executed, drastic reorganisations of their urban cores to accommodate the car. Buchanan expressed a similar level of zeal for the project of urban reorganisation as Castle had for bringing order to the chaos of the wider transport network, stating in Traffic in Towns: ‘This is really a matter of faith in our own future as a nation. If we believe we have a great future then we must also believe that . . . we shall have the resources to remould our environment to our liking.’

Castle’s ideals for transport, though similar to Buchanan’s in scope, addressed the needs of users at a more personal level (not least because, in her words, ‘one just can’t find the money for his schemes’). Scandalised by the shocking rate of fatalities on the roads — running at 8,000 in 1966 — she pushed through the Road Safety Bill in 1967, which established compulsory breath tests for motorists suspected of drink-driving, safety belts in cars, and a seventy mile per hour limit on the new motorway network.

The policy saved thousands of lives almost immediately, for which she was rewarded with death threats from motorists and a year’s worth of patronising media coverage regarding her own lack of a driver’s licence. The lorry drivers’ union also accused her of putting ‘a spy in the cab’ for legislation requiring lorries to carry tachographs, preventing hauliers from driving for too many hours without a break.

Having established that she didn’t want to put private cars out of business — which, she believed, ‘had brought the boon of mobility to millions of people’ — but only to make roads safer, Castle turned her attention to public transport. In Red Queen, her biography of Castle, Anne Perkins notes that Castle’s years commuting by train between Westminster and Blackburn had given her ‘first-hand knowledge of railway stations with no regular linking bus services, erratic local connections and . . . under-investment in rolling stock and track improvements.’ For Castle, ‘the fate of British Rail was a matter of personal familiarity as well as political concern.’

Brought into public ownership in 1948, British Rail’s heavy losses were considered unsustainable and trains believed to be on their way out. In 1963 an infamous report by Richard Beeching led to the network being cut by 5,000 miles and 2,000 stations. Beeching had been appointed by Castle’s Conservative predecessor, Ernest Marples, who — strangely enough — owned 80 per cent of the road construction company contracted to build Britain’s first motorway, the M1. Marples ordered Beeching to consider only the financial benefits of losing or retaining each line.

When Castle took on transport much of the first Beeching report was being implemented along these lines, with ‘uneconomic’ branch lines being closed all over the country. It required a complete redefinition of what the railway was for — a social good, a public service bringing ‘the boon of mobility’ to those without cars — to save the rest of the network.

Castle did this by reclassifying British Rail’s debts and by allowing loss-making routes and branch lines to continue with cross-subsidy from heavily-used routes. Without it, the entire railway west of Plymouth or Newport or north of Newcastle might have closed, leaving a skeleton ‘basic railway’ of only 3,000 km rather than the 11,000 or so we have now.

Granted, those lines that were saved were subject to cost-cutting by other means: staff levels were cut back, stations lost their ticket offices, and drastic measures such as the introduction of the ‘railbus’ — literally, old buses converted into shonky trains — kept lines alive, but at a severe cost to the convenience and comfort of the user.

Working her way through the mountains of legislation that formed the 1968 Transport Bill — at over 2,000 pages, the longest piece of post-war legislation up to that point — Castle sought to extend the idea of mobility-as-a-social-good through the creation of Passenger Transport Authorities and Executives for major urban centres outside London, which gave regions the power to make decisions based on local users’ needs.

It was through these that the Tyne and Wear Metro light-rail system and Birmingham’s Cross-City rail line were built, both of which helped to maintain and even increase public transport use at a time of growing car ownership. Castle commented warmly on the ability of PTEs to build safe, convenient interchanges where people could get off the train and wait in the warm for a bus without having to cross town in the rain.

The 1968 Act even added coaches to the government’s portfolio of state-run transport, creating the National Bus Company (later known as National Express) to deal with intercity and holiday road transport, as well as nationalising the canal and inland waterway network, which led to the rehabilitation of canals for public and leisure use.

The transport infrastructure inherited by Barbara Castle in 1965 was at a tipping point, where the coming of mass car use was viewed as an inevitable sign of economic progress and individual freedom. Trams had already disappeared from the urban landscape; buses and trains were thought to be not far behind. Her foresight and intervention as transport secretary prevented the bus and rail network from becoming as sparse and unfit for purpose it is today in the US.

Fifty years after the Transport Act, car ownership is falling once more, the railway is growing again — and ripe for renationalisation — and the political dominance of the private motorist may finally have had its day. That moment can’t come too soon.