Comp Site - Miami-Dade Circle at SW 107 Ave & SW 176 St

First REAL comp-site note in the vault — built per Comp Site - Miami-Dade Traffic Circle (worked example). Every factual claim below traces to a source in the Sources section; unfilled fields are explicitly flagged, not guessed.

Location & context

Site: SW 107 Ave & SW 176 St, unincorporated Miami-Dade County (South Miami Heights area, Miami-Dade Commission District 9 per the county project listing). · Roadway type: local residential grid streets, 2 lanes (1/dir). · Posted speed: not published in project sources — confirm in field or from county speed-zone records. · Context: single-family residential grid west of US-1/Cutler Bay — confirm land-use detail from current aerial before using in a deliverable. Problem being solved: intersection operations/safety on a residential grid — the county lists the project as “Intersection Improvements”; the specific triggering study (speeds, crash pattern, petition) is not public — request from DTPW Traffic Engineering if the memo needs it.

Program & policy basis

• Miami-Dade DTPW Traffic Engineering runs the countywide program: it investigates “hazardous traffic conditions” and makes “recommendations for the installation of traffic control and calming devices countywide” — DTPW Traffic Engineering page (checked 2026-07-08).
• Traffic circles are an explicitly named device in the county’s traffic-calming toolbox: the 2025 County–City of Miami interlocal amendment (Legislative Matter 250368) lists “traffic circles, speed humps, historic wayfinding signs, raised intersections, speed tables, speed cushions, chicanes, and mid-block raised crosswalks” as the traffic-calming devices covered (checked 2026-07-08 — see Sources).
• The program is still actively building circles: a June 2026 county solicitation (No. 20250181, MCC 7360) covers traffic circle construction at N Miami Ave & NW 163rd St (checked 2026-07-08 — see Sources).

What was built

• Treatment: new traffic circle at the intersection. Official scope (verbatim, DTPW weekly construction report): “clearing and grubbing, drainage installation, construction of Traffic Circle, installation of curb and gutter and sidewalks, milling and resurfacing, adjustment of valves, installation of pavement markings, signage, and sodding.” — Project No. 20200231 WO #4, Commission District 9.
• Approximate year: under construction by July 2022 (report anticipated completion August 2022); later reports in the same series (Oct 2022) pushed anticipated completion to December 2023. Exact acceptance date not published — date the build from historical aerials (FDOT APLUS / Google Earth slider) per Workflow - Comparable Sites Research.
• Circle diameter, splitter/approach geometry, YIELD signing layout: not in public sources — measure from aerial / request county standard detail from DTPW. Do NOT quote dimensions until then.
• Same report series documents sibling installs, useful for a comp table: retrofit of an existing circle at SW 97 Ave & SW 120 St (Project No. 20200255-R, District 8 — geometry fix of NE corner, new ped crossing, two warning flashers, lighting) and a new circle at NW 11 St & NW 30 Ave (Project No. 20200031 WO #1, District 5).

Observed outcome

• No site-specific before/after study is published for this circle. Not claimed.
• Program-level context only: the county’s Old Cutler Road traffic circles page cites FHWA national roundabout statistics (“90% fewer fatalities and 75% fewer injuries”) — national numbers, not this site, and Old Cutler is a collector corridor, not a local street. Use for agency-attitude evidence only; for effectiveness use CMFs (Countermeasure Selection and CMFs).

Applicability — lessons for Tampa Bay

• Precedent, same state: a Florida county DTPW routinely constructs traffic circles on local residential grid streets through its capital program — directly usable as agency-acceptance evidence for a Hillsborough/Pinellas local-street calming request.
• Grid context matters: the site sits in a connected residential grid (alternate routes exist), matching the context screen in the workflow — check the Tampa candidate for the same.
• Delivery model: built as a work order under a districtwide intersection-improvements contract (Project 20200231 WO #4), not a one-off — evidence that a programmatic contract vehicle keeps unit costs and delivery predictable.
• Delta to address in the memo: Miami-Dade’s request/qualification criteria (petition thresholds, study triggers) were not published with this project; Hillsborough’s program scoring differs — state the difference explicitly rather than implying identical processes.

Sources

1. Miami-Dade DTPW, “Roadway Construction Report for the week of July 25–31, 2022” — names Project No. 20200231 WO #4 at SW 107 Ave & SW 176 St with full scope. Original county URL is offline (site reorganization); verified via Internet Archive: http://web.archive.org/web/20220722111048/https://www.miamidade.gov/releases/2022-07-22-DTPW-weekly-construction-report.asp (checked 2026-07-08). Source class 1 (official).
2. Miami-Dade DTPW Traffic Engineering program page: https://www.miamidade.gov/global/transportation/public-works/traffic-engineering.page (checked 2026-07-08). Source class 1.
3. Miami-Dade Legislative Matter 250368 (2025) — interlocal amendment enumerating traffic-calming devices incl. traffic circles: https://www.miamidade.gov/govaction/matter.asp?matter=250368&file=true&fileAnalysis=false&yearFolder=Y2025 (checked 2026-07-08). Source class 1.
4. Miami-Dade solicitation 20250181 (MCC 7360), “Traffic Circle Improvements at N Miami Avenue and N 163rd St” — program currently active: https://www.miamidade.gov/apps/isd/StratProc/Home/SolicitationDetails?solNumber=20250181+%28MCC+7360%29 (checked 2026-07-08). Source class 1 (context).
5. Miami-Dade DTPW, Old Cutler Road Traffic Circles page (program-level context; FHWA stats are national, not site-specific): https://www.miamidade.gov/global/transportation/old-cutler-road-roundabouts.page (checked 2026-07-08). Source class 1 (context only).

Open items before this note is deliverable-grade: aerial before/after pair (FDOT APLUS + Google Earth) to date the build · county standard detail or as-built for circle geometry · posted speed confirmation · DTPW study/petition record request.

See also: Comp Site - Miami-Dade Traffic Circle (worked example) · Workflow - Comparable Sites Research · Workflow - Research and Source Vetting · Traffic Calming Toolbox