Following last summer's East Gardiner boondoggle vote, the project's proponents—the City of Toronto and Waterfront Toronto—have been left with the difficult task that of overseeing what threatened to become a sort of shotgun wedding of the revamped 'Hybrid' expressway and the urban realm. In the months since the June 2015 Council vote to build a 'hybrid' highway, the initial option was sharpened into three more concrete and urban-friendly proposals by City Staff in September, while a number of third-party options have also come to light. On January 19th, the City and Waterfront Toronto presented a more thorough evaluation of potential hybrid designs—including third-party plans—as the latest step in fine-tuning the expressway into a somewhat more urbane and economically viable piece of infrastructure.

The report evaluates each of the City's three hybrid options, while also giving consideration to two notable third-party proposals; the 'Green Gardiner' and the 'Viaduct.' While benefits of the third-party proposals were acknowledged, the report ultimately warns that both plans would be extremely costly, while infrastructural obstacles also would also likely hinder the viability of either. Meanwhile, a more detailed comparison of the three 'Hybrid' configurations balances the costs and complications of construction/maintenance with environmental impacts, urban design, and long-term economic benefits.


The well-publicized 'Green Gardiner' plan proposes moving the Gardiner directly over the rail tracks and covering 1.1 kilometres of the expressway with an elevated green space. The plan would allow for any of the three Hybrid solutions to be implemented to its east, while freeing up three hectares of public land for new development.

Green Gardiner Plan by Brook McIlroy, SvN, and Entuitive

The report identifies that the plan would cost at least an additional $735 million—while making some of the ongoing revitalization efforts redundant—and would likely be subject to a highly complex Metrolinx approvals process, while also complicating traffic flow by removing a westbound exit at Jarvis. Nonetheless, the benefits of the Green Gardiner plan are such that the idea could be revisited in the future, after more immediate Metrolinx plans are implemented for the corridor. 

The report also provides an analysis of a 'Viaduct' proposal which would see a large earth berm—and a cable-stayed viaduct stretching between Sherbourne and Parliament—integrate the Gardiner into its surroundings in a less imposing manner. The report recognizes that the lower profile of the bermed sections would allow for comparatively unimpeded views across the corridor,while potentially allowing for more development on either side of Lake Shore Boulevard.

Though the life-cycle costs of the termed sections would be comparatively low, the plan would cost an additional $485 million over hybrid costs, while requiring the acquisition of 12 privately owned sites nearby. according to the report, costly—and probably lengthy—negotiations with landowners make the idea less attractive. Meanwhile, the viaduct itself would only be possible in 425 metres of the 1,700-metre corridor, while some north-south pedestrian crossings would need to be be lengthened to accommodate the new infrastructure.  

The report identifies that both third-party proposals are ultimately unfeasible within the life-cycle of the existing Gardiner East, especially considering ongoing rehabilitation efforts would amount to a lost expense. Nonetheless, the design teams responsible for these proposals helped to inform the shape of Hybrid designs east of Cherry Street, while the report acknowledges the long-term plausibility of the Green Gardiner once current Metrolinx plans are implemented. However, it was reasoned that since the Viaduct option would only provide strong benefits to a short section of the Gardiner, the cost-benefit ratio is too high. 

Aerial view of development possibilities associated with the Hybrid 3 option, image by Waterfront Toronto


The bulk of the report focuses on a comparative analysis of the three 'Hybrid' concepts first presented in September. While these plans have been somewhat revised and fine-tuned in the months since, each of the three concepts still largely corresponds to the September plans. According to traffic projections for the updated designs, however, all three options are now expected to have the same travel times and capacity, despite the somewhat slower ramps of options 2 and 3.

Concept 1

The first option presented is also the most similar to the base hybrid concept voted on in June. Like the initial hybrid option, Concept 1 routes part of the expressway immediately alongside the Keating Channel, separating the water from the urban realm. The major change, however is the tighter curve of the ramps, which reduces the Gardiner's local footprint, opening up more land—a total of 5 acres—for potential development. Preserving a continuous connection between the Gardiner and the DVP, the plan removes Logan on/off ramps in line of new access at Cherry Street.

The urban design for the Hybrid 1 concept, image courtesy of the City of Toronto and Waterfront Toronto

Concept 2

In the second revised concept, more significant changes are made to the base hybrid option, with the expressway now moved slightly to the north, allowing for more new development along the Keating Channel, for a total of 7.5 acres. Under this configuration, Lake Shore Boulevard would run directly underneath the expressway through this stretch, opening up more land for green space and public realm improvements. Removing the Logan on/off ramps in favour of new connections, the also plan offers an improved public realm with development potential directly along the Keating Channel. 

The urban design for the Hybrid 2 concept, image courtesy of the City of Toronto and Waterfront Toronto

Concept 3

The final concept presents a variation of 'Concept 2,' turning off of Lake Shore sooner, and unlocking the same amount of potential development land. In order to facilitate the tight alignment of ramps presented in this option, the underpass beneath existing CN rail bridge over the Don River (below) would need to be widened in order to allow for the Gardiner's ramp curves to start further north. This concept would allow for a more naturalized Don River, and likely offer the most benefit to the environment and to urban design of the public realm. Concept 3 is also the most expensive option.

The urban design for the Hybrid 3 concept, image courtesy of the City of Toronto and Waterfront Toronto


While the three concept plans work within relatively similar parameters, there is some difference in projected costs—divided into construction and maintenance expenses—for each option. The maximized public realm and environmental benefits of Concept 3 come at a price, slightly increasing the overall cost (below).

A projected breakdown of the total costs, image courtesy of the City of Toronto/Waterfront Toronto

Broadly speaking, the report identified Concept 1 as having the greatest economic benefits. This category is aggregated by measuring by the total costs of construction and the impact of trucks and services during the construction timeline. While Concept 1 is projected to be completed within 4 years, Concepts 2 and 3 would be expected to take 5 years.

A comparison of the relative benefits of each option, image courtesy of the City of Toronto/Waterfront Toronto

However, in terms of environmental impact, urban design, and long-term transportation and infrastructure impacts, Concepts 2 and 3 clearly stand out ahead of Concept 1. Concept 3 appears to be the most beneficial overall option, improving the pedestrian/cycling activity while also providing the least amount of above-grade development to hinder the area's urban design and built form. The additional development land facilitated by Concepts 2 and 3 would also help to offset some of the increased costs of construction and maintenance, making these options more attractive.

What do you think of the potential Gardiner plans? Since we will already be spending half a billion dollars more for the least expensive hybrid option over the removal option, do we spend another $100 to $150 million more to do a better job of it?  Feel free to join in the conversation by leaving a comment in the space below, or by contributing to the ongoing discussion in our Forum. A full copy of the report from the January 19 presentation is also available here