The redesign of the bus network should make greater use of the M50, An Taisce has said.
The environmental and heritage charity said a “major oversight” in the proposed and existing network is the “minimal use” by buses of the M50.
In its submission to the National Transport Authority (NTA) regarding the BusConnects plan, An Taisce said the proposals come "at a time when the need for a reform of Dublin's transit system comes from several pressure points".
It said investment and modernisation of public transport infrastructure is “critical” in order to deliver radical and further reductions in greenhouse gas emissions.
An Taisce's Climate Committee said it supported the majority of the BusConnects plan, which includes the construction of core, high-speed bus corridors, the addition of orbital routes, integrated and simplified ticketing, the development of a network of high-quality cycling routes and park-and-ride facilities.
However, it said one major oversight in the proposed plans is the minimal use of the M50, “which is by far the most important orbital in the city”.
"In other cities of comparable size, for example Ottawa, Canada, the main city motorway artery or ring is critical to linking cross-routes and creating the vital network effect to ensure increased ridership, high modal share and reduced network subsidies," it said.
“In Dublin, planning to include the M50 as a major orbital route linking all major radial routes is surely critical to success of BusConnects.”
Transport Infrastructure Ireland warned in its submission there may be "limited availability" within the existing national road corridors to accommodate some of the proposals. It pointed to a number of national roads that are proposed to be used for spinal and orbital bus routes, namely the M50, N3, N4, N11 and N81.
An Taisce also said the BusConnects fleet acquisition process must prioritise “the very lowest emissions technology that is available and technically suitable”.
It acknowledged the plan promises to fully transition to a fleet of “low-emissions vehicles” by 2030, with half of the fleet transitioning by 2023.
“At the moment it is undetermined what low-emissions vehicles might mean, and the plan states that research is currently ongoing, which was also the message received at local information sessions,” it said.
The charity said that despite gains for many Dublin residents, the redesign involves “an inherent trade-off with the accessibility for vulnerable groups such as elderly and disabled”.
It said if the provision of additional services, such as a community transport service, were to be considered, “this trade-off simply disappears”.
Some 30,000 submissions were received by the NTA in relation to the redesign of Dublin's bus network
“An investment such as an urban community transport service would be in keeping with a sustainable transition which ensures that nobody is left behind by the network redesign,” it said.
“Aside from being a matter of justice, this would also galvanise support for BusConnects, which has faced significant local scrutiny since the plan was released.”
An Taisce said the integration of Dublin Bikes would be a “simple and sensible addition” to the multi-modal ticketing system.
It added that financial incentives are important but that the BusConnects plan “seems to make no mention of discounted fares for regular users, such as weekly, monthly and annual ticket holders”.
“This needs to be considered as a means of increasing patronage, in combination with measures to make driving more costly for those who do not need it,” it said.
Some 30,000 submissions were received by the NTA in relation to the redesign of Dublin’s bus network when public consultation closed at the end of September. A revised network is due to be published by mid-2019, and a further round of public consultation will begin.
Aside from a redesign of the network, the BusConnects project also involves upgrading 16 core bus and cycle lanes into the city. Earlier this month, details of the first four proposed corridors were released by the NTA.