Last month, Washington DC was graced with a shiny new form of public transport. It promises to zip eager passengers around the capital of the land of the free at astonishing speed and great value.

Or, at least that’s what the city’s transport authorities would have you believe. As it happens, DC’s new streetcars – trams, to those of us on this side of the pond – are the ultimate in damp squib infrastructure involvement. The city spent an estimated $200m on just  2.4 miles of line, running along H Street from behind Union Station (yes, behind) to about halfway along Benning Road NE, where it intersects with Oklahoma Avenue. (A second route, the Anacostia line, was partially constructed in 2009-10, but then abandoned; other lines have been proposed, but so far nothing more.)

As if that weren’t disappointing enough, the line has been delayed so many times that its eventual launch came seven years after it was supposed to be up and running in 2009 – and 13 after the idea was first mooted in 2003. A former mayor of the city, Marion Barry, put it rather nicely when he deemed the project “ill-planned, ill-thought-out, ill-engineered, ill-everything”.

A map of the current streetcar route. Click to expand. Image: DC Streetcar.

What, then, can we learn from the failure of the Washington DC streetcar “network”?

First up, commit to public transport.

If, as a politician or bureaucrat fortunate enough to play toy trains as an actual, real-life career, you decide to build a new bit of public transport infrastructure – whether a new train line, ferry service, or an upgrade of the bus rolling stock – then you might as well go for it properly. Most of the time, it’ll require a lot of political manoeuvring, the ability to withstand an election or two, far too many meetings, presentations, reports, and committees. All that requires somebody to be really committed to the idea in the first place.

DC’s streetcars seem bizarrely half-hearted. Trams are most commonly associated with quaint old European cities like Prague, Berlin, and Lisbon. Most of these lines have segregated lanes – segregated road space set aside so that trams can pass freely and easily. This, one might think, is a requirement.

But not in DC. As such, there have been repeated accidents, with streetcars crashing into the backs of cars who have strayed into the streetcar lane. You can actually watch videos online of streetcars having to stop and sit and wait while some idiot moves their car out of the way.

If you’re going to do it, do it. Build a little curb, have a segregated tram way, pedestrianise the area, do whatever it takes. Don’t just have a vague attempt at it and expect applause when you say “viola” seven years too late.

If you’re building a new line, don’t use an existing route.

When key routes on exist public transport networks become overcrowded, you need to find some extra clever infrastructural trick to ease things up and increase capacity.

You might, for example, do as TfL’s “New Tube for London” is hoping to do, by improving the actual vehicles themselves so that they can run more quickly, more regularly, and carry more passengers. Or you might go for the Crossrail approach – build a new line that connects lots of the key transport hubs and interchange points, but across a slightly different route, thereby giving your customers more options and easing up the existing routes.

What you probably shouldn’t do, though, is build a new thing that’s actually just a duplicate of the existing thing. The grandstanding, record-breaking 2.4 mile route of the streeetcar is, all other qualms aside, already covered by a public bus route, the X2.

Other proposed routes. Click to expand. Image: DC Streetcar.

Yep: there’s already a bus, managed by the DC transport authority, running up and down that exact stretch of route. Well, not exact, as pedants will note that the streetcar stops slightly closer to Union Station than the X2 does.

But the point stands – there’s already a happily functioning transport route in action, and the average speed of the streetcar is slower than that of the bus. You’d think it would be obvious that the aim of building public transport is to replace private transport or offer alternatives to other public transport options, not just duplicate perfectly what’s already there. You’d think.

Don’t think you can just copy the models of cities you like.

This one’s less of a problem specific to the DC streetcar, and more a Mean Girls-esque “you can’t sit with us”, only for international transport geeks.

Essentially, it’s very tempting to go to cool cities and think, “Wow, I travelled on this really awesome public transport system and I want one for my city!” Normally that’s fine, because you’re a nobody, so you just go home and write article about why Swindon should get a cable car network like Medllín’s, or that what Glasgow and Edinburgh really need is a maglev line between them.

But when you’re a transport official in Washington DC, when you can nip over to Europe on holiday, find you rather like the quaint old trams, and think they’d be a lovely thing to have back home – then you are doing a bad and dangerous thing. Trams work in European cities because they’re old and tightly packed. The closely-huddled streets of the centre of European cities weren’t designed for motor traffic, and old cobbled streets make driving at any great speed a singularly unpleasant experience.

In America, though – and in DC in particular – cities were planned on grand scales, covering large distances, and with cars (or, at the very least, horse-drawn stagecoaches) already in mind. There’s a reason that the Americans do suburbs and gas-guzzling beast cars in a way that Europeans can only squirm uncomfortably at.

Which leads nicely on to this one:

If something’s already been tried and has failed, there’s probably a good reason not to do it again.

As historian John DeFerrari explores in a new book, “Capital Streetcars: Early Mass Transit in Washington, DC”, the city has already done streetcars. From the late 19th century right up until 1962 they racketed up and down DC’s streets, carrying citizens in from outlying areas, first in horse-drawn streetcars, and then eventually in electric streetcars.

Then came the invention of the car, which meant that everybody upped and moved to the suburbs, and enjoyed being able to eat as many packets of cheese and onion crisps en route as they liked without anybody giving them the Paddington Bear death stare. Similarly, along came public buses, which were faster and more comfortable than the existing streetcars.

In other words: DC, you’ve done streetcars. They were nice, they made for good sepia photos for 21st-century hipsters to frame and put in their bathrooms, and everybody appreciated you as historical fact. But they died. they failed. There’s no need to bring them back.

Perhaps most importantly, you have to:

Establish a clear timetable for delivery, and then actually stick to it.

We get it. Building stuff takes a long time. There’s politics and bureaucracy before you even get to money, planning, engineering, and construction. It’s going to take ages.

That said, most of the time people don’t mind waiting for stuff if they a) have a clear idea of how long they’re going to wait, and b) can trust that the indication is reliable.

Think of it this way – if you go to a theme park, and see that your favourite ride has a 5-minute wait time, you’ll optimistically jump in the queue. If it then takes you 90 minutes to get on the ride, you’ll be grumpy, grouchy, and encased in a fiery ball of rage as you spend the rest of the day stropping around the park distrustfully eyeing up the many LED signs promising that it’ll only be 10 minutes until you can ride the teacups for the seventh time today.

Crossrail is taking a horrendously long time to build. It was properly started in 2009, and it won’t be completely finished and open to the public until the end of 2019. Yet in spite of near-apocalyptic overcrowding on most tube lines in rush hour, most people aren’t up in arms, marching on Boris Johnson’s rather swanky townhouse demanding that he personally intervene to speed things up, because it seems to be going to plan. Crossrail has given people a set of intermediary deadlines to get certain sections and rebrandings done, and it has thus far done them.

Berlin’s mythical Brandenburg airport, meanwhile, is the opposite. It was supposed to open in 2012. It’s now 2016 and, well, it hasn’t. You’re much better off giving a pessimistic schedule that can then be trumped, than an optimistic one that you’ll miss.

It’s also worth taking the time to actually:

Work out how much people are going to have to pay to use it.

One of the big political selling points of the DC streetcar was that it would connect a lot of the poorer eastern areas of the city to the downtown core. Given that, it seems faintly bizarre that the transport authorities haven’t actually worked out how much they’re going to charge their passengers yet.

The line is going to be free for the first six months – which is almost certainly why the ridership figures have been pretty reasonable for the opening weeks – but at some point after that, it’ll cost some kind of money. The rumours say $1, in line with the city’s Circulator system; but it could be $2, three silver sickles, or £4 for all we really know.

Nonetheless, those passengers that the Washington Times spoke to said they probably wouldn’t use it if it wasn’t free. And when people get used to not paying for a thing – as they would do over six months or more – they’re probably not going to be very happy when you try and get them to cough up.

Last but not least:

Do not do anything that might encourage your transport development to go viral on social media.

The “Elizabeth Line” got slaughtered on social media (Crossrail was doing so well before BoJo got gimmicky). Meanwhile, the Emirates AirLine has been rendered pitiful by Twitter’s commendable send-up.

From what I can tell, the DC streetcar has so far been protected from this fate. This isfrankly surprising given how bizarre, humiliating, and cringeworthy its “How to Ride” video is.