COMMENT ANALYSIS The National Transport Authority are proposing to off the main road Marino and Fairview as part of the Clongriffin BusConnects Core Bus Corridor. The Malahide Road narrows as it approach and there isn’t the space to accommodate the desired road layout of the National Transport Authority (NTA).
The decision to divert cyclistswas based on analysis undertaken by engineers working for the NTA. It found that when you consider all of the pros and cons that diverting cyclists was the most preferred option. However, there are two flaws with this.
The diversion uses low-traffic and low-speed residential roads in Marino. Though local residents are trying to stop some motorists using these roads as a rat run.
This is a good alternate route for cyclist leaving the city. In fact many cyclists already use it to avoid the main road. However, for cyclists heading into the city it is a poor option as it requires them to wait at two extra sets of lights.
The NTA have published the full multi-criteria analysis behind the decision to divert cyclists. This analysis examined four options to determine what was the best option based on 5 criteria: economy; transport integration; accessibility and social inclusion; safety and environment.
The four options were:
- Scheme 1: southbound bus lane, and cycle tracks in both directions
- Scheme 2: divert all cyclists through Marino. Bus lanes in both directions
- Scheme 3: divert southbound cyclists through Marino, provide an northbound cycle track and an southbound bus lane
- Scheme 4: divert northbound cyclists through Marino and southbound motorists via Copeland Avenue and Howth Road. Bus lanes in both directions
After weighing up all of the pros and cons the engineers found that Scheme 2 was the most preferred option. However, there are two flaws in the analysis.
Flaw One: Scheme 3 should have won
In the end there was little scoring different between Scheme 2 and Scheme 3. Scheme 2, which diverts all cyclists, only beat out Scheme 3 on the environment criteria. On initial inspection this seems odd. Scheme 2 has a total road width of 15.6m compared to 14.35m for Scheme 3. How did the wider option have less impact on the environment? The answer: a mistake was made.
The environment criteria is based on seven sub-criteria. Scheme 3 performed better than Scheme 2 on the Flora and Fauna criteria. The narrower option had less impact on plants and trees in front gardens. However, Scheme 2 performed better than Scheme 3 on the Architectural and Cultural Heritage criteria. It found that Scheme 3 would have an impact on the “boundaries of two protected structures”, numbers 62 and 64 Malahide Road and Scheme 2 would not. It’s strange that the wider option doesn’t impact on the protected structures but the narrower option does.
Scheme 3 is the option in the public consultation. On map 20 you can see that the NTA proposes to move the boundaries of the protected structures. Scheme 2 and Scheme 3 should have the same score for the Architectural and Cultural Heritage criteria.
Taking all of this into account Scheme 3 should have a better environment score than Scheme 2 and it should have been selected as the overall most preferred option.
Flaw Two: Comparing apples and oranges
The second flaw is that the analysis doesn’t always compare like with like. Scheme 1 provides cycle tracks in both directions. From a purely cyclist point of view this is the best option. The NTA analysed this option, which is 17.2m wide.
At 17.2m it is much wider than Scheme 2 (15.6m) and Scheme 3 (14.35m). As the widest option it has the largest cost and the greatest impact on the environment. In Scheme 2 and Scheme 3 the proposed footpath was the minimum allowed width of 1.8m. In this option they are 2.2m and 2.5m. This increases the width of the cross-section by more than 1.1m, which adds to the cost and environmental impacts.
It’s odd that they’re proposing a 1.8m footpath beside bus lanes but propose wider footpaths beside a cycle track. The NTA is not comparing like options with like options, which is the second flaw.
Northbound bus lane
Scheme 1 and Scheme 3 do not include a northbound bus lane, which is the current situation. Buses and general traffic would share for the first 180m of the Malahide Road. Based on the NTA’s report and traffic queue length data this could cause delays for buses, but is unlikely. The benefits of an outbound bus lane could be achieved using other bus priority measures such as bus-only traffic lights.
When the NTA repeat this analysis they should add a new option that includes southbound cycle track and diverts northbound cyclists. The currently proposed diversion is acceptable for northbound cyclists but a poor option for southbound cyclists. The NTA should also consider options with wider footpaths and cycle tracks than the current options, especially since options like Scheme 3 are 1.1m narrower than the currently proposed option.
Determining the best option for this short section of Malahide Road will not be easy. But it is vital that the analysis that underpins this decision is solid. Currently it’s not and it should be repeated.
Kevin Baker is a member of the Dublin Cycling Campaign. All of the above information is included in the Dublin Cycling Campaign’s submission on the Clongriffin CBC.