Manor Park / Vanier · Streets

A traffic circle at Hemlock and St-Laurent is possible. The approved plan just refused to try one for size.

The cheap idea is still the right first idea: slow the left turns at Hemlock Road and St-Laurent Boulevard with a small circle, tight corners, or even a hay-bale trial. City staff did not refute that with a turning count. They buried it under a 5.2-kilometre signal corridor.

This is the record of what the September 2025 functional design actually says, what it does not say, and where “no room” stops being engineering and starts being politics.

What the City passed

Public Works and Infrastructure Committee approved the St-Laurent Boulevard Transit Priority Corridor recommended plan on 25 September 2025. Council followed on 8 October 2025. The study runs from Hemlock Road to Innes Road / Industrial Avenue. Price tag: about $260 million. Priority construction is Lemieux to Innes before 2046. Hemlock to Lemieux comes later.

Segment 1 — Hemlock to north of Montreal Road — is the quiet end:

two travel lanes
buses in mixed traffic
2.0 m cycle tracks and 2.0 m sidewalks on both sides
a new mid-block pedestrian crossover between Meadowpark Place and Karen Way
no bus-only lanes on this stretch

Protected intersections are specified at all signalized intersections. Hemlock is named as one of three intersections — with Montreal and Donald — where the phased design shrinks the footprint so the City can defer property takes.

Correction that matters. The staff report also says the plan “removes auxiliary left-turn lanes at three locations.” It does not name those three locations. Treating Hemlock as one of them is an inference only.

Why a circle keeps coming back

The local problem is not the whole boulevard. It is the Hemlock lefts: drivers coming off a minor street onto an arterial, cutting across the through movement, with buses in the mix and a neighbourhood on both sides of the north leg.

A neighbourhood traffic circle, or even a temporary island, does one job well. It forces a yield and kills the straight-line left. Ottawa already uses mini-roundabouts in its traffic-calming toolkit. Ottawa also builds real roundabouts — dozens of them — and is putting one on Jeanne-d’Arc so buses can turn around. Staff are not allergic to circles. They are resistent to a circle that breaks the corridor kit they already sold.

That kit is: signals, transit signal priority, protected intersections, protected cycle tracks. Ottawa’s own collector-road guidelines then do the rest of the work. Do not mix control types on a corridor. Do not put a roundabout just upstream of signals. Drop bike lanes before the circle or put cyclists on a bypass. Watch transit stop locations. Give extra thought to elderly and visually impaired pedestrians, who lose the accessible pedestrian signal they get at a light.

Those are real operating issues. They are not a proof that a compact single-lane roundabout is impossible on a two-lane, 50 km/h segment.

The tape measure

This is the part that is needed.

Chart 1. Street width versus circle size

Existing character area

23–30 m

Official Plan protection

26 m

Object	Typical size	What it can take	Fits Hemlock pavement?
Hay-bale / mini-circle	13–25 m ICD	Cars. Buses ride the apron or cannot make the left cleanly.	Yes, as a trial.
Urban compact roundabout	25–30 m ICD	City bus, tight.	Maybe, if corners move.
Urban single-lane	30–40 m ICD	Bus plus WB-15 truck.	Not inside the 26 m street. Needs property.
Two-lane roundabout	45–55 m+ ICD	Higher volume.	No.

The four corners

“There is room” counts if the quadrants are empty. They are not at oresent.

Corner	What sits there	Can you use it for a bigger circle?
Southwest	Beechwood Cemetery. National Historic Site. Statutorily bounded on the north by Hemlock and on the east by St-Laurent. National Cemetery of Canada.	Only with a heritage and expropriation fight the EA already refused. Staff wrote “no impacts” to Beechwood and Notre-Dame but let's be real.
Northwest	Manor Park North. Secondary Plan puts a 9-storey mixed-use gateway building on this exact corner — 206 / 244 St-Laurent, 869 Hemlock and related holdings.	Council needes to shrink it or move the building it designated.
Northeast	Manor Park houses and local commercial.	Front yards. Ordinary property politics.
Southeast	More houses and commercial south of Hemlock, east of St-Laurent.	Same. Nibble possible. Not enough by itself for a 35–40 m circle.

A symmetric bus roundabout needs all four corners, or it becomes a lopsided oval that buses can still track. Lawn inside the cemetery fence is not spare right-of-way but it is still there. A planned gateway tower is not a grass boulevard but it can be modified.

Chart 2. Who actually blocks the larger circle

The first two bars are legal and planning commitments. The last bar is the one people mean when they say staff bias. All five are in play. They are some kind of real obstacle.

Transit is a constraint. It is not a veto.

Staff say ten OC Transpo routes use St-Laurent, plus deadheads to the garage. Route 7 is mapped across St-Laurent / Hemlock / Brittany. In Segment 1 those buses stay in mixed traffic. The plan buys them signal priority, not a reserved lane and not a circle.

A single-lane roundabout can take a bus if the inscribed diameter and apron are available. What it cannot do is give the bus a green light. Every bus yields. That is an operations choice. If the City’s real goal at this node is reliability for Route 7, a circle still works. If the real goal is slowing the Hemlock lefts, the circle still works.

Bias, path dependence, and will

Ottawa’s written policy is to consider a roundabout when an intersection needs new control. The city has on the order of 85 roundabouts. Calling staff merely “anti-circle” is too simple.

The bias that does exist is path dependence. Once the environmental assessment picked signals and protected intersections for 5.2 kilometres, Hemlock stopped being allowed to be a different intersection. Mixing a circle at the north terminus with signals downstream is exactly what the City’s own guidelines warn against. That is institutional habit. Habit is a form of bias. It is not the same as “circles don’t work.”

The clean split.
A mini-circle or tightened Hemlock radii: engineering yes. Political maybe. Worth doing now as a trial.

A compact single-lane modern roundabout: engineering maybe if Council takes land and puts cyclists on a bypass. Political no under the plan already passed.

A full arterial roundabout with cycle tracks threaded through it and no property take: no. The tape measure already answered that one.

Political will can reopen the plan, buy the east-side yards, move the gateway building, and spend the money. Will cannot invent a 40-metre circle inside a 26-metre street without those takes. Will cannot make Beechwood into leftover boulevard by calling the grass a shoulder. Will cannot make a hay-bale island a design vehicle for an articulated bus (the city has started removing these).

So yes: the live ìssue is whether Council wants to treat Hemlock as its own intersection instead of the north cap on a signal system. That is politics. The cemetery, the buses, and the fixation on limited metres without using whats actually there are not.

What to ask for next

If this is going to move put three sheets on the table:

The latest City turning-movement count at St-Laurent and Hemlock, peak hours, with heavy vehicles broken out.
A one-page sketch of a 28–32 m single-lane ICD with bus swept paths, cycle-track bypass, and PXOs on the approaches — overlaid on the existing parcels.
A property take list limited to that sketch, separate from the 79-property corridor number.

If staff cannot produce (1), they have not studied the node. If they can produce (2) and the takes are only east-side yards, the “no room” line collapses. If (2) clips Beechwood or the gateway floorplate, then the fight is exactly the political fight it looks like.

Until then, the honest public sentence is short. A small circle would tame the Hemlock lefts. The City did not design one. The reason is the corridor package they already locked, plus a cemetery they will not touch. That is enough..

Sources

City of Ottawa, ACS2025-PDB-TP-0013, St-Laurent Boulevard Transit Priority Corridor Recommended Plan (Public Works and Infrastructure Committee, 25 September 2025).
City of Ottawa news release, Committee approves plan to improve transportation along St. Laurent Boulevard, 25 September 2025.
City of Ottawa, project page, St-Laurent Boulevard Transit Priority Corridor EA.
City of Ottawa presentation PDFs: st-laurent_presentation_en.pdf; st_laurent_presentation_en.pdf (ROW 26 m Hemlock–Montreal; 44.5 m Montreal–Innes).
City of Ottawa, s. 5.6 Roundabouts, Village, Collector and Rural Arterial/Collector Road Design guidelines.
City of Ottawa, Roundabouts; Pedestrian crossovers.
City of Ottawa, Jeanne-d’Arc transit measures (roundabout for buses): project page.
CBC News, What’s with Ottawa’s love-hate relationship with roundabouts?, 21 October 2024 (city policy to consider roundabouts; ~emissions and safety claims).
CTV News Ottawa, Navigating Ottawa’s roundabouts, 7 November 2024 (city figure of 85 roundabouts).
FHWA / NCHRP roundabout geometry, commonly cited ICD ranges: mini 13–25 m; urban compact 25–30 m; urban single-lane 30–40 m; urban double-lane 45–55 m. See also TAC Canadian Roundabout Design Guide (2017).
St. Laurent Boulevard (Ottawa) — posted speeds 40 km/h north of Hemlock; 50 km/h Hemlock to McArthur.
Parliament of Canada, Bill C-408 (39-1), designation text: Beechwood “bounded on the north by Hemlock Road, on the east by St. Laurent Boulevard.”
Beechwood Cemetery maps and site materials: beechwoodottawa.ca.
City of Ottawa, Manor Park North and South Secondary Plan — gateway building at St-Laurent and Hemlock.
City of Ottawa staff report on Manor Park holdings (206 / 244 St-Laurent, 869 Hemlock, northwest quadrant): escribemeetings Document 4021.
OC Transpo, Route 7 map (St-Laurent / Hemlock / Brittany).
Open Ottawa: Transportation Intersection Volume 2023; Transportation Midblock Volumes 2024; collision data 2017–2024 (excluding 2023) on ArcGIS.
Ottawa Citizen, Aedan Helmer, Manor Park sidewalks get the OK, 30 March 2026 — Councillor King ranking Hemlock, Sandridge, Birch and St-Laurent as the higher-volume local streets.

PeterKarwacki.blogspot.com.
Figures are from the public EA text, City guidelines, and the geometry tables cited above. They are not a surveyed plan of the intersection.

Friday, 18 September 2026

#527 Traffic Circle at St.Laurent and Hemlock