Going through 50 years of Tunnels & Tunnelling archives, there is one major difference practically leaping off the page. The reasons cities build tunnels.

In an advertisement from 1979 a now defunct firm promotes its civil engineering services with the line “Tunnelling…to ensure an uninterrupted traffic flow.”

Today clients extol the benefits of their projects with a focus on efficient transportation, sustainable travel, clean waterways and other livability improvements to their voting and tax-paying residents.

Dealing with congestion is under-emphasized, even when it’s the benefit many residents will most likely appreciate. Urban planning and design is increasingly embracing congestion as a way to deter people from choosing vehicle travel when public transportation or walking/bike journeys are an option. This is happening in several London, UK, neighborhoods.

Whereas, in the 1979 July/August issue of this magazine the editor’s comment opens “London is the only major capital city in the industrialized world without a proper motorway ring road.” It goes on to suggest how imperative it is to build a multi-lane, freeway in London; suggesting the 1980s would be a good time for the city to build this infrastructure, particularly underground. Spoiler alert, it didn’t.

Currently London’s mayor is making a concerted effort to reduce air pollution and health risks caused by vehicle use by promoting bike travel, closing streets near schools, and charging a fee for higher emission vehicles to enter the city.

The crux of any major city’s traffic and air quality is embracing walkable, bikeable streets and providing frequent and efficient public transport. But there are still journeys in urban environments that must be done by vehicle for deliveries and construction work among other reasons. Seattle is demolishing its viaduct while vehicular traffic passes through the new SR 99 tunnel. Discussions of replacing Toronto’s Gardiner Expressway, or at least sections of it, with an underground option resurface every few years. There is also a burgeoning industry for autonomous vehicles, not to mention car sharing programs and ride hailing apps. These are changing the way we travel in cities and use streets.

“Driving in a tunnel is not pleasant by comparison with the open road, but, taken all in all, may be preferable to driving in busy city streets,” wrote the editor. In 40 years, the experience of individual drivers has disappeared from the planning conversation. The benefits to going underground haven’t changed.