A cycle track from Artane to Clontarf is planned to be too narrow, but is there a way to fix it?

Comment & Analysis: Once cycle tracks are segregaed, the usable width of a route is one of the fundamental determining factors of whether a cycle path/track is high quality or not. Dublin City Council’s Gracefield Road to Vernon Avenue Walking and Cycling Scheme fails the test.

With the Gracefield Road to Vernon Avenue Walking and Cycling Scheme, which runs between Artane to Clontarf, the public consultation is over. Updated drawings have been uploaded (reports and full drawings can be found at Dublincity.ie).

Dublin City Council is looking to move on to construction with cycle tracks that are now too narrow, have too much reliance on shared spaces, and have other related issues.

There is a solution that does not require much extra space for the cycle route overall…. switching to a longer two-way cycle path… but using a two-way cycle path should be based on solid reasoning, which benefits the quality of the cycle route…

First, an overview: The project is 2.60km long with 1.9km of unidirectional cycle tracks on each side of the road (lighter green below), and just under 0.7km of a two-way cycle path in the middle section (darker green):

There have been a number of complaints about the width of the nearby Griffith Ave cycle route, some saying they are nervous about cycling on it because of its width. Many school children also choose to cycle on the much wider footpaths, partly so they can talk to their friends while cycling (‘social cycling’).

Many users have also said that the more generous cycle tracks on the Clontarf to City Centre route are still too narrow for comfortable overtaking — not just for the volume of people cycling but even outside of rush hour.

If the city council continues to roll out cycle paths with little or no learning from what has been built to date or acceptance of public feedback from previous projects, support for projects will start to suffer. Cycle routes need to be attractive enough for people to want — or even demand — more of the same.

Some people in Ireland and other countries dismiss Dutch cycling design guidance because “we’re not the Netherlands”. They say, “We don’t have their levels of cycling”. But the new Dutch guidance on width comes with a detail that it is a minimum width “regardless of intensity”.

• “The minimum width needed by two cyclists to cycle side by side safely and comfortably, regardless of intensity. This minimum width is set at 230 centimetres.” (2.3m)

This evidence-based guidance is based on the increase in various shapes and sizes of cargo bikes and the rise of ebikes — the extra width of bicycles and the speed of others, and also allowing for social cycling. We also should really be targeting beyond 2 metres. It’s worth noting that the Dutch measurement excludes the width of kerbs and other buffers.

And while some cities around the world can scoff at the idea of cargo bikes being popular, Dublin isn’t one of those places. There is strong growth in the use of cargo bikes in Dublin, especially in areas where decent cycle paths have been installed.

The width of a cycle track or cycle path is also a key section of Ireland’s Cycle Design Manual produced by the National Transport Authority. The manual outlines how there are four elements:

• A = Inside Clearance; the space to the left of cyclists which is determined by the inside edge/boundary of the cycle facility.
• B = Central Width; the space required for cycling which depends on the type of facility, direction of flow and anticipated volume of cyclists.
• C = Outside Clearance; the space required to the right of cyclists which is determined by outside edge/boundary of the cycle facility.
• D = Buffer; the horizontal separation required between the cycle facility and traffic, which is determined by the speed limit of the road.

Based on the table on the Cycle Design Manual’s Width Calculator (PDF page 26) and looking at the drawings and photomontages for this project, the following would be the ranges of widths which are desirable and the “absolute minimum” for this project depending on the exact details (which I cannot tell for sure so a range is offered below):

	Desirable minimum width	Absolute minimum width
A = Inside Clearance	0 to 0.25	0 to 0.25 (depending on kerb type and height, which is not clear)
B = Central Width	2.0	1.5
C = Outside Clearance	0 to 0.25	0 to 0.25 (depending on kerb type and height, again, which is not clear)
D = Buffer	0.50	0.2 to 0.3 (not per guidelines, but because there is a kerb)
	2.5m to 3m (including 0.5m kerb/buffer)	1.7 to 2.3m (including kerb)

The width of the cycle track on most of the Vernon Avenue Walking and Cycling Scheme is just 1.75m, including its kerb! This is the general width shown on all of the unidirectional cycle tracks as part of the project.

That’s just about above the “absolute minimum width” and far from the 2.5m desirable and 26% narrower than the Dutch minimum recommended width.

It’s a standard width across all of the unidirectional sections of the route:

I don’t think Ireland should be including kerbs or buffers in the cycle path width — we should be looking at usable width separate to any buffer. Even if a kerb is planned to be level with the cycle path surface, there are known issues why people might not want to have to rely on that in any way. So, a lot can hinge on kerb design detail and construction quality, and, later, maintenance.

With the project, we don’t have detailed kerb drawings, but the photomontages do not show exactly flat kerbs:

The photomontages also show points where the inside kerb becomes a higher kerb where an inside width of 0.25m would be needed:

An important point here is that the terms cycle tracks/lanes/paths are often interchangeable, but when I say cycle track in this article, I mean a “stepped cycle track” where the segregation is lower than normal footpath height found on most main roads.

From the perspective from the cycle path, the Gracefield Road to Vernon Avenue cycle track (photomontage) looks much the same as the recently built Deansgrange cycle path:

A difference is clearer from the carriageway side — motorists will mount a cycle track shown in the photomontage in the first image with ease. The higher kerb on the Deansgrange cycle path is a little more defended:

As a side note, the Gracefield Road to Vernon Avenue route has a notably higher kerb on its two-way cycle path section (this is another photomontage):

The switch from unidirectional paths to a two-way path and back to unidirectional paths means that there are two crossover points.

As the route crosses the Howth Road it includes a Dublin-style junction, which, by design, is unlikely to be both effective for all modes and safe for children cycling on the route. It makes little sense that at other junctions walking and cycling are mixed, but, here, we need traffic lights to govern the interaction:

The other crossover point is at Vernon Ave around the southwest corner of St Anns Park — again, the apparent need to keep pedestrians and cycling controlled by signals here in a suburban context and in contrast to other nearby junctions doesn’t make sense in terms of the design making sense to users and being efficient:

The alternative

Without removing all the trees, one solution to the narrow width of the route is to extend the two-way section in both directions.

Here’s the proposed vs a continuous two-way route:

	Proposed	Continuous two-way
Cycle path/track	Narrow and does not allow for comfortable overtaking or social cycling on most of the route.	Some include mixing pedestrians and cycling on shared footpath-like areas, and other designs try to use signals to govern walking and cycling interactions.
Bus stops	Narrow “shared boarding” areas where ~1m boarding area between bus stop doors and cycle track.	Cycle path is only on one side so half the number of stops to deal with and more scope for wider boarding areas.
Junctions	Some junctions include mixing pedestrians and cycling on shared footpath-like areas, and other designs try to use signals to govern walking and cycling interactions.	More consistent design with pedestrians and cycling kept apart to a far larger extent and clear crossing points where they interact.
Some smaller junctions	Segregation is missing along sections.	More changes for segregation.
Bridge across Dart line	Too narrow to segregate.	Segregation.

The below image shows the proposed route as it crosses the Howth Road and, under it the two-way design:

A wider view of the same junction:

Another example junction showing how a two-way path can improve flow for the cycle route while reducing shared spaces and improving accessibility at the bus stops:

There’s some reluctance to put two-way cycle paths across driveways, but two-way paths can work with driveways as per Deansgrange and other routes:

And, finally, the non-signalised junctions as part of the proposed design are similar to what’s already built on the Deansgrange Road — just bidirectional: