There’s a reason the Luas trams won’t switch between lines

Last week, the Luas team published its new route map, including the Cross City line.

Due to go into service in December, the new line, despite being shown on the route map in blue, is essentially a continuation of the Green Line.

There will be an interchange at Abbey Street where passengers travelling on the Red Line will get off and walk to O’Connell Street to hop on the Luas Cross City or vice versa.

Some wondered why the new service doesn’t allow for trams to switch between the Red Line and the Green Line. Could we not have just joined them up? Why the interchange at all?

Firstly, it’s a myth that Luas trams can’t transfer between the Green Line and the Red Line, says Hugh Creegan, deputy chief executive at the National Transport Authority.

“There is no difference in track widths or power supply,” said Creegan, by email. “A tram currently operating on the Red Line can also operate on the Green Line and vice versa.”

There are “engineering links” between the Red Line and the new Luas service, says Creegan, but these are only for “vehicle maintenance”. So the Luas trams still won’t transfer between lines carrying passengers.

Not everybody might be aware of that, says Green Party Councillor Ciarán Cuffe, who is head of the council’s transport committee.

“I think this was known amongst the trainspotters for quite some time, but for the lay person, they’re wondering if you can seamlessly hop from one train to another or have a choice of different trains bringing you to different destinations,” he says.

Independent Councillor Paul Hand says it would have made sense to have the two lines crossing over. “People have mentioned it and it has come up at the Transportation SPC,” he says. “I think it’s a no-brainer that they should be linked.

“It’s a bit bizarre,” says Hand. “It definitely makes sense for the Red line Luas to be able to go [directly] to Cabra and vice versa for the Green Line Luas to be able to go the Point Depot.”

But there is a reason that can’t happen.

Less Waiting

Creegan of the NTA says that rail systems like the Luas generally work best when there is single high-frequency route that intersects with another single high-frequency route. In other words, two separate line that don’t join.

“If services are frequent you have very little delay and the transfer can be largely seamless.  London Underground and the metro systems in most cities are examples of this arrangement,” he said.

The alternative is a “multi-leg” system, which would slow everything down, he says.

As an example, under such a system, one-third of the trams from Broombridge would go to Tallaght, another third might go to the Point, and the remaining third might continue directly onto the Green Line.

But the Luas can only manage about 20 trams for per hour, one every three minutes, in each direction through the city’s streets.

So the way it works out with a multi-leg service “could mean a nine minute wait for people who wanted to travel in any of these directions”, Creegan says. “This is a much less attractive service and more people have to wait longer for their journeys.”

“So instead of trams services going through Westmoreland Street and Dawson Street every three minutes, it would become every nine minutes, down from 20 an hour to 7 or 8 an hour.”

More Talk

Fine Gael Councillor Paddy McCartan says he thinks the public won’t take issue with the Abbey Street interchange when the Cross City opens later this year.

But Luas Cross City could do a better job letting people know what’s going, he says. “It’s a radical transformation and you have to bring the people with you.”

That could be as simple as improving the route map released last week, says the Green Party’s Cuffe.

He says the map is unnecessarily confusing for people, something editor of the New Statesman‘s City Metric, Jonn Elledge, also complained about last week.

“I think the Luas Cross City team have to up their game in communicating what’s happening over the next several months,” says Cuffe. “They need to rapidly improve that [map].”