Suir Road to Thomas Street cycle route is a no brainer but its design is too poor

Comment & Analysis: The Suir Road to Thomas Street cycle route really makes a lot of sense to prioritise as a quick-build route — it’s on a local road where rat running needs to be tackled and it will help link up other planned routes. But — as with many projects — the design needs improving.

What’s planned is due to start construction on Tuesday but the details of this project will have to be adjusted sooner or later.

Dublin City Council has the highest levels of cycling in the country, but paradoxically its quick-build cycle lanes are maybe the narrowest, especially at pinch points where other choices could be made on “politics of space” choices.

If built according to the drawings the council has published online, this project includes what may be one of the worst examples of narrow cycle paths.

The marking on the left shows less than 1.5 metres for two-way cycling at the junction — this measurement is copied from the Dublin City Council 1.5 metres measurement to the right side of the image.

The new National Cycle Manual has an “absolute minimum width” of 2 metres and a 3 metres “desirable minimum width” for low-volume two-way cycle paths with no or low, splayed kerbs on both sides.

But these types of widths aren’t what any council should be aiming for — a two-way cycle path on a primary cycle route in a city centre area like this should be 4+ metres wide.

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Of course, there will always be pinch points but less than 1.5 metres for a two-way cycle path which (1) on a small incline, (2) at a junction and (3) beside a wall on one side, is nothing short of outrageous — all of these factors should increase the need for extra width.

On DLRCC’s Coastal Mobility Route, which was built on a route which has a higher thought traffic need, the traffic lane widths for motorists are between 2.5-3 metres. The balance can be made towards the cycle path to the point that emergency services would be better off using the cycle path).

Dublin City Council is using a traffic lane width of 3.6 metres:

There were alternatives here:

(1) A better balance between the cycling and motoring space, as per the CMR example mentioned above.

(2) Filter the road (ie with bollards) so that a cycle path isn’t needed but residents have two-way access.

(3) Male the cycle path contra-flow only — although without reducing peak traffic flows this is probably a really poor solution.

Just east of the junction, the westbound direction of the cycle route is merged with motor traffic anyway along the section shown here in yellow:

It also feels like impossible requirements are being put on cycle route design teams compared to the current situations provided to facilitate car parking:

Yet at different points along the route, traffic lanes which are extra-wide are provided at the detriment of the width of the cycle path:

When you add in that there’s a desire to retain car parking here — I’m told for good reason — it seems all the more of a question as to why some kind of traffic  filter which would allow two-way car acces but not through traffic wasn’t tried.

Elsewhere on the project, there are some strange decisions and then there are wonderful ones…

Traffic lane widths which will encourage speeding:

One of the stranger decisions is a new mini-roundabout… is it really needed here?

And, a very welcome decision is giving priority to the cycle route crossing motor traffic, which is great to see.

A ramp for motorists at the northern approach or having a raised junction treatment could be solid additions here:

Although it’s not clear what this is about? There’s space here to have the marked cycle route line up better or for the cycling entry point to be protected:

The shared street here with two-way cycling while making the road one-way for motor traffic will enable added width to the currently really narrow footpaths:

But sharing, even for a short section, might not work as well on Marrowbone Lane which probably has the highest level of traffic on any of the streets which are part of this route.

On this section of Marrowbone Lane, there’s currently perpendicular parking:

Part of it looks like it will be removed and set down spaces provided:

But this drawing is vague as to what will happen to the other half:

Regardless of what is to happen, a large chunk of the cycle lane is shown as unprotected on both sides (note the dotted white lines) and the extra unnecessary width is given to the traffic lanes when the cycle tracks could be 2 metres wide.

This is a 30km/h street, there’s no need for traffic lanes which are 3.3m wide:

The footpath buildout at the end of the current phase of the project makes little sense — the cycle lane is narrow here at a bend in the road… Why narrow it down further?

There’s even a question should the cycle lanes along this section have been combined into a two-way path on the northern side of the street?


  1. Disappointing. Weren’t we promised a two-way segregated cycle lane to Thomas Street? Marrowbone lane is really not that different to what is here now. Also cyclists who don’t want to go onto Thomas St itself (T St & Chiristchurch & Lord Edward St & Dame St total nightmare for less confident cyclists) will somehow have to get into the middle of MBL to take a right into Pimlico and the quiet road network that leads more safely & pleasantly to Grafton St area. The rat run from Rialto Bridge to the Maryland is in my experience full of fast moving, impatient, close-passing drivers. I’ll be cycling along the linear park (north of Luas track) to get across Rialto.

    • I absolutely agree. That junction, Thomas St, Lord … is a recipe for disaster when a less than confident and even confident bicycle users negotiate turns, changing of lanes, and simply avoiding the dangers of large motorised vehicles converging with little or no awareness of/regard for, vulnerable road users.

      Such priority given to private cars, taxis, ..
      has to end.

  2. @Cian – update on this. Cycle lane yet to be segregated. There is a place just down from the bridge where it goes from being one way to two way and it is LETHAL. Cycling within the lines eastbound I nearly got run over on Friday by a woman in a massive SUV turning left onto the traffic lane. Then another motorist virtually drove right at me to avoid the parked cars. Turning left from that narrow street onto Marrowbone lane is also lethal. There is not enough space to see cars coming into town along MBL and right-turning cars cut the corner. Very close shaves a couple of times. To give the councillors their due, it’s a great idea in principle but those points unless looked at could result in injuries/fatalities.


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