Case Study: Lower Don Lands Master Plan Environmental Assessment

Problem: The ‘Lower Don Lands’ is a large area of brownfields located on the waterfront area in the City of Toronto. It will be the next area of the waterfront to be revitalized. Although its revitalization will pose complex technical challenges, it has exceptional potential to create an exciting and beautiful new waterfront district with a unique identity. The plans for the Lower Don Lands, if implemented, will establish the City of Toronto as a world leader in developing sustainable urban communities and the restoration of degraded natural landscapes.

Successful implementation of the Lower Don Lands is also critical to opening up the rest of the vast vicinity to revitalization. The revitalized ‘Lower Don Lands’ will be a new urban district of mixed-use communities focused on the re-naturalized Don River and the historic Keating Channel. It will have a population of between 20,000 and 24,000 residents in approximately 12,000 housing units, and a range of employment space. Streets and trails would be extended through the precinct including Queen’s Quay, a re-aligned Lake Shore Boulevard, Cherry Street, Martin Goodman Trail, Don River Trail, the Lake Shore Boulevard trail and the water’s edge Waterfront Promenade. The new ‘south boulevard’ design for Queens Quay in East Bayfront will continue to Cherry Street, beyond which Queens Quay will become a local street connecting to Lake Shore Boulevard.

A major initiative in the Keating precinct is to improve north/south connections at three underpasses of the rail corridor. A new pedestrian underpass to the Distillery District at Trinity Street would be created. The existing Parliament and Cherry Street underpasses would be enlarged to provide more space for pedestrians and cyclists. The Cherry underpass would also accommodate street car service.

Challenges: The analysis was performed using a microsimulation model. Microsimulation models are more sophisticated than standard traffic analysis tools and allow users to test the impacts of congestion on multiple modes of transportation on a larger network. Microsimulation models also provide better representation of queues and their interaction with adjacent intersections, a function not found in other types of modelling platforms. A microsimulation model was selected for this project for many reasons, but primarily to model the interaction of multiple modes of transport such as autos, streetcars and pedestrians.Additionally, there is significant development proposed along the waterfront, and the collective impact of this development has not yet been tested on a larger network.

Finally, there were various levels of development that were proposed for the site and this is easily tested in a microsimulation environment. In terms of microsimulation analyses, there are many platforms that can be used. The two most commonly used platforms in North America are Paramics and Vissim. Both tools have their strengths and limitations. Vissim is best suited for corridor modelling where modes may share lanes. Paramics is better suited for modelling larger networks, with a high degree of route-choice.

Due to the size and complexity of the network, and the many possible routing patterns around the new developments, Paramics was selected as the preferred microsimulation modeling tool. The Paramics model was developed using the City of Toronto’s regional model to represent travel demand and transit information.

The network study area is bounded by, and includes, Jarvis Street to the west, Queen Street to the north, Leslie Street to the east and the waterfront to the south.

Conclusion: To quantitatively assess the mobility needs, the design team developed a microsimulation model using Paramics and a corresponding set of performance measures. This analysis compares the development scenarios by evaluating various performance measures.

These performance measures were developed with the broader sustainable mission in mind and include multi-modal measures such as person delay which factors in the delay felt by each person within a vehicle, thus ensuring that high occupancy vehicles such as buses and streetcars are prioritized over lower occupancy vehicles.

The performance measures include multi-modal measures such as person delay, transit delay, pedestrian crossing times, pedestrian waiting times, transit travel times and vehicle travel times. Through an evaluation of the transportation alternative solutions, a preferred solution was identified and carried forward as the Transportation Master Plan.

The Transportation Master Plan was developed to balance the needs of the various uses that would be served by the transportation network, while recognizing urban design and pedestrian environment considerations. The Transportation Master Plan consists of the individual pedestrian, transit, bicycle and road networks as well as the individual streets connections.

Together, these address the Study’s Problem Statement and meet the needs and transportation objectives of the study, which are:

• Shift towards non-auto modes

• Prioritize transit

• Increase and improve the pedestrian network

• Increase and improve the bicycle network

•Rationalize parking

• Improve the public realm Infrastructure

Improvements recommended from this study will be further developed during detail design. Future design work will include confirmation of details such as road excavation and transit requirements, construction staging, as well as pipe sizes and specific locations for water, wastewater and stormwater treatment facilities.

Eddie Lam.  City of Tronto / Arup


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