By Lorne Ross, February 2020
Grade Separations: Info. Sheet 5
Metrolinx is increasing its
services as part of the GO Expansion program, which will increase train
frequency and the number of trains on the GO rail network. To increase traffic
flow and transit capacity, Metrolinx has identified the need to build a number
of grade separations.
This Info Sheet describes:
• What is a grade separation?
• Why are grade separations
needed? What are the benefits?
• What is involved in
designing a grade separation?
• What is involved in
building a grade separation?
• How will Metrolinx design,
build, and address effects of grade separation?
• Why doesn’t Metrolinx move
tracks instead of the road?
What are the benefits of grade separations?
• Improved traffic flow and
elimination of the potential for conflicts between trains and vehicles;
• Increased on-time
performance and operational reliability;
• Better connections and
crossings for pedestrians and cyclists;
• Reduced noise from level
crossing signals and train whistles; and
• Air quality benefits from
reduced car idling;
• Opportunities to bring
roads up to new standards, such as wider lanes and wider walks, separated bike
lands, or improved lighting.
What is a
grade separation?
A grade separation is a
tunnel or a bridge that allows a road or rail line to travel over or under the
other, without the need for vehicles travelling on the road to stop. If the
road is lowered below the rail line, it is called rail over road, while if
it is raised above the rail line, it is called road over rail.
Why are grade separations
needed?
Although
each rail line is different, trains may run as little as one or two times per
hour on some Metrolinx corridors. This means that each road crossing may need
to be temporarily closed about once or twice an hour to let the trains pass.
With
GO Expansion, all-day 15-minute service could mean that a train will pass every
7.5 minutes – greatly increasing the number of interruptions at each road
crossing.
By
grade separating crossings, Metrolinx can safely increase travel speed and
capacity on our roads and rail lines. Grade separations allow trains to freely
pass over or under roads without the need for the road traffic to stop.
What is involved in designing a grade separation?
Road overpasses require a
new structure to raise the road above ground level. The structure could be held
up by piers or retaining walls. Depending on the width of the road, the rail
line would pass under the new structure through a tunnel or under a bridge.
Road underpasses usually involve excavating a
trench for the road, that is held by retaining walls on each side. Depending on
the crossing, a new rail bridge is usually built to cross the underpass at the
lowest point.
In designing grade separations, Metrolinx is
guided by a variety of objectives, including:
• maintaining and/or
improving connectivity and access to properties and businesses;
• minimizing noise and negative visual impacts;
• minimizing construction and
maintenance costs; and
• minimizing the project
footprint, including acquiring properties and removing vegetation and trees
only when necessary.
What is involved in building a grade separation?
Grade separations are large
construction projects, and Metrolinx is committed to managing construction to
minimize their effects on communities.
Temporary construction
effects are similar to most construction projects, and may include:
• Traffic disruptions,
including possible detours or closures around construction areas;
• Nuisance effects such as noise and dust;
• Removal of vegetation or
temporary property impacts near construction zones; and
• Possible service
disruptions to utilities from relocations.
As part of the GO Expansion
program, Metrolinx is planning the following grade separations (also see the Discussion Guide):
1. Denison St, Road Underpass
2. Kennedy Rd, Road Underpass
3. Passmore Ave, Road Underpass
4. McNicoll Ave Road Underpass
5. Huntingwood Dr, Road Underpass
6. Progress Ave, Road Overpass
7. Danforth Rd, Road Overpass
8. Wellington St, Road Underpass
9. McNaughton Rd, Road Overpass
As GO Expansion continues
along with population growth in our urban centres, Metrolinx will work with
local municipalities to consider the need for more such crossings.
How will Metrolinx design, build, and address the effects of grade
separations?
Metrolinx will work closely
with local municipalities, stakeholders, and residents to identify and manage
the potential effects of grade separations. This process will include:
• Completion of relevant
environmental assessment studies to identify effects and appropriate mitigation
measures, including specific studies to address key community concerns, such as
traffic, tree removal, and effects on adjacent land uses;
• Community consultation related to project design
and mitigation;
• Working groups with
municipalities and utilities to address conflicts and look for opportunities to
coordinate construction work;
• Early engagement with
potentially affected property owners to discuss compensation options; and
• Construction management
plans to minimize construction effects related to noise, dust, traffic, and
other environmental impacts (e.g. keeping two lanes open for local traffic in
construction zones).
To learn more about
Metrolinx’s new approach to construction management, please read Info Sheet #6.
Why
doesn’t Metrolinx move the tracks instead of the road?
Although it may seem
simple, even small changes to a rail line can have big challenges, including:
• Stricter standards for trains – trains have stricter standards for curves and
slopes to operate safely, meaning
that raising or lowering a rail line similar to a road could require up to six
times as much space.
• Higher costs – Because of the design and engineering challenges, redesigning and reconstructing a rail line is more
expensive than road work.
• Limited options for detours – The ability to detour a rail line is very
limited because of the size of the
corridor and can affect service along the entire route. Roads on the other hand
can be addressed by limiting lanes, building detours, or using adjacent
streets.
• Safety risks – Construction within a rail corridor presents safety concerns, so
limiting the amount of work next to
active trains is always preferred.
This Info Sheet is part of
a package of Info Sheets and a Discussion Guide provided by Metrolinx to share
updates on system-wide studies and policies. The current set of Info Sheets
cover a number of different topics, including: GO Expansion benefits, heritage
conservation, vegetation removal and compensation program, electromagnetic
fields and electromagnetic interference, and new approach to construction
management.
For more information
For more information about
GO Expansion and to download other materials, check out our website:
MetrolinxEngage.com
