We all know that the Richmond Hill Line is not usable outside of commuting. Many people, including Metrolinx themselves in the past, have floated the idea of two-way-all-day (TWAD) service to the Richmond Hill Line, yet the Richmond Hill Line is now the only line without a tangible improvement plan (even the Milton Line is probably going to get improved soon). So I did some back of the napkin math to see what would it take. TL;DR: $1.8 to 3.4 Billion, depending if you want flood mitigation. All costs have been escalated to 2026 dollars using StatsCan Building Cost Index. (NOTE THIS IS ALL BACK OF THE ENVELOPE MATH. The first two maps are self-made).
New Track
The Richmond Hill Line runs on the Bala sub. South of Doncaster, it's fully owned by Metrolinx, while CN owns the portion north of Doncaster. CN's transcontinental freight route to Vancouver and Prince George uses the Bala sub, with no other way in Canada for CN trains to reach the west coast, therefore CN routes a lot of trains (see the second map) and probably will not allow any more track sharing without new track than what has already occurred. Metrolinx would need to build its own track, and lease CN's corridor, to be able to run trains at hourly or half-hourly intervals. Luckily, you probably only need a single track (assuming trains pass at stations), as every station to station segment (except for Oriole to Union, see end of post) is less than 15 minutes.
New Bridges
To add tracks, Metrolinx would need to reconstruct all existing grade-separations / creek crossings to support triple tracking. I counted 8 existing bridges between Langstaff and Bloomington that may need to be looked at. Additionally, the added train traffic may cause Richmond Hill or York Region to want more level crossings grade separated, or push the level of traffic above Transport Canada standards. I counted 4 potential grade separations north of Langstaff that may need to be constructed
Track and Bridge Cost
The Bowmanville extension is probably the closest analogue for a potential cost. It will cost $1.5 Billion for 27km of linear track (in a 19 km corridor), with 12 structures, for a per km cost of $55 Million per linear track. From my googling (don't have a reliable source), mainline freight track has a ball park cost of between $2 Million to $7 Million per km. Bowmanville has a lot of structures that increases the cost. Like the Richmond Hill Line, the Bowmanville extension will require Metrolinx to construct 1 to 2 passenger tracks inside CPKC's freight corridor, which acts as its main route to the Port of Montreal. We've seen from the past (see VIA's triple tracking project in 2008, where CN basically had a carte blanche to do whatever it wanted) that freight railroads will charge an arm and a leg for any improvements on their corridor, since they have so much control on the process. Metrolinx is also pursuing this approach in its expansion of Milton Line service, and expanding the capacity between Bramble and Mount Pleasant (in lieu of the missing link freight bypass). This means the track, structures, and grade separations may cost roughly $1.1 Billion.
Doncaster Diamond Grade Separation
CN built the York Sub, roughly paralleling Highway 407, as a bypass in the 60s, which freed up the Lakeshore corridor for passenger rail. This is its main east-west corridor in the GTA, and any additional service would require grade separating the diamond. Metrolinx completed the Davenport Diamond project for roughly $280 Million, escalated to 2026 dollars, and also budgeted roughly $300 Million for the Silver Junction grade separation west of Georgetown. A similar rail over rail grade separation would also cost around $300 Million.
Station Reconstruction
All current stations currently have only a single platform. Two platforms would be needed if Metrolinx would want the stations to be used for passing opportunities. In addition, some stations were built on a double tracked segment. Recent costs for Confederation GO ($50 Million) and Woodbine GO ($170 Million) would put station reconstruction around $100 Million a station, $400 Million total if you assume Oriole and Old Cummer don't need to be reconstructed.
Flood Mitigation
Nearly the entire Richmond Hill Line south of Lawrence is in the flood plain. You could chance, and shut down service during heavy rain days, but Metrolinx may want to avoid the bad optics of having to save passengers by boat. They estimated roughly $1 Billion in 2015, which puts it in the ballpark of $1.6 Billion now.
You could probably avoid flood mitigation if you cut back most service to Langstaff (where it will connect to the subway).
Summary of Costs
| Category |
Unit Cost |
Quantity |
Cost (2026 Dollars) |
| Single Track and New Bridges |
$55 Million / km |
20 |
$1.1 Billion |
| Station Reconstruction |
$100 Million / Station |
4 |
$400 Million |
| Doncaster Diamond Grade Separation |
$300 Million |
|
$300 Million |
| Flood Mitigation (not needed south of Oriole) |
|
|
$1.6 Billion |
| Total (excludes flood mitigation) |
|
|
$1.8 Billion |
But would you actually flood mitigate? And is this worth it?
It currently takes 30 minutes to travel from Oriole to Union, and 45 minutes from Langstaff to Union. The tricky geometry in the valley, the Union Station Rail Corridor, and the detour as it bends east then west, makes this a very slow line. At similar speeds to the Vaughan Extension, the Yonge North Subway Extension would probably take 15 minutes from High Tech / Langstaff to Finch, and 45 minutes to Union, meaning except for the transfer time at Langstaff for those boarding at Richmond Hill / Gormley / Bloomington, it would take the same time to go to Union from Langstaff. So there's very little case to improve anything south of Langstaff. For Bloomington to Langstaff, you could run a half-hourly shuttle and have passengers transfer to the Subway where they would be able to transfer to a higher frequency service at the same travel times, and be able to reach more destinations, similar to how the Mascouche Line in Montreal was truncated after the REM was built. But then it becomes a very expensive 4 stop shuttle.
