Chapter 1 · EV39

Reversible Street Pilots Scaled Successfully

Date collected: 26 May 2026

Summary

Temporary street reconfigurations piloted, evaluated, then made permanent; low-cost reversibility reduces political risk, accelerates AV-ready infrastructure iteration

Conceptual Framework for Ch.8

Street space reallocation pilots—when designed with clear exit criteria, reversible modifications, and genuine community engagement—can scale to permanent systems while maintaining public support. Four case studies show conditions under which temporary pilots became permanent policy.

Case 1: Oslo City Centre Pedestrianisation (2015–2019)

Pilot Phase

Timeline: Declared 2015; piloting began 2017
Initial scope: Six pilot trials removing ~300 parking spaces in central Ring 1
Trial locations: Dronnings gate, Fridtjof Nansens square, and others
Design: Reversible; pilot duration ~1–2 years per location before expansion decisions

Expansion (2017–2019)

Phase 1 (2017): 300 parking spaces removed in Ring 1
Phase 2 (2018): Major expansion; traffic routes altered; several streets closed to vehicles
Total removal: ~800 parking spaces removed city-wide by 2019
Duration: Full rollout completed within 2 years

Measured Outcomes

Car traffic reduction: 28% decrease in inner-city car traffic
Pedestrian activity: 10% increase in pedestrian volume in city center year-over-year
Public support: 75% support for overall goal (3 of 4 residents) by completion
Key factor: Strong early public acceptance despite initial skepticism

Governance Mechanism

City Council declaration (2015) set clear political mandate
Pilot trials allowed adaptive management; locations adjusted based on early feedback
Community engagement emphasized quality-of-life framing (street life, culture, events) rather than abstract sustainability claims
Reversibility: Some measures (e.g., temporary bollards) could be removed within weeks; public knew this

Scaling Conditions

Political mandate at top: City government committed before pilots; not consensus-driven
Rapid iteration: Multiple pilots in parallel, not sequential; faster feedback
Concrete benefits visible: 10% increase in pedestrians and 28% traffic reduction were measurable within 1–2 years
Cultural fit: Oslo already had car-skeptical population; not fighting strong car culture
Reversibility communication: Public knew changes were not irreversible, reducing opposition

Application to CAM Governance

Pilot phases with clear metrics (e.g., “If CAM adoption reaches X% market share, curb lane will be converted to X use”) can gain public acceptance
Cities should announce expansion criteria in advance, not post-hoc, to build credibility
Temporary infrastructure (painted curb lanes, movable bollards) less politically contested than permanent removal

Sources:

Case 2: Barcelona Superblocks (Pilot→Expansion, 2016–Present)

Pilot Phase

Timeline: Pilot launched ~2016; initial evaluation 2017–2019
Scope: Sant Antoni superblock (pilot #1); Horta neighborhood (pilot #2)
Design: 9-street perimeter reducing through-traffic; local traffic allowed; speed limits 10–20 km/h
Reversibility: Could be redesignated within months if needed

Evaluation Methodology (Pre-Post)

Health survey: 1,200 residents, pre-post design
Environmental measurements: NO₂, PM10, PM2.5, black carbon at multiple locations
Pedestrian activity: System for Observing Play and Recreation in Communities (SOPARC)
Walkability assessment: Microscale Audit of Pedestrian Streetscapes (MAPS)
Traffic injury data: Injury rates pre-post

Pilot Outcomes (Sant Antoni)

Air quality: NO₂ down 25%; PM10 down 17%
Noise: Daytime noise reduced 4.1 dB; nighttime 5.3 dB
Pedestrian comfort: 60%+ residents felt more comfortable walking interior streets
Accessibility: Improvements for strollers and people with reduced mobility reported
Health projection: If expanded city-wide, estimated 700 deaths per year prevented

Expansion Plans

Target: 500 superblocks by 2030 (currently ~10 active/piloted)
Status: Scaling from pilot phase to city-wide program based on demonstrated results
Political backing: Strong city government commitment to expand despite car-culture opposition

Governance Mechanism

Evidence-first approach: Rigorous pre-post evaluation before expansion decisions
Transparent metrics: Published health/environmental data built credibility for further expansion
Incremental scaling: Phased rollout (superblock by superblock) not city-wide mandate
Community feedback loop: Early pilots informed design of subsequent blocks

Scaling Conditions

Rigorous measurement: Health and environmental data made expansion politically defensible
Health framing: CO2 reductions alone would not have driven expansion; health benefits (700 deaths/year prevented) was the key political driver
Reversibility: Superblocks are not permanent infrastructure removal; traffic diversion could be reversed
Incremental scale: Expansion one block at a time, not wholesale; easier to adjust course
City-wide vision: Department of Urban Ecology framed superblocks as part of larger mobility transformation, not isolated pilot

Application to CAM Governance

Metrics matter: CAM governance should define measurable success criteria (e.g., “If CAM reduces total vehicle-miles by X%, curb will be repurposed”) before pilot
Health/equity framing: Environmental and health benefits, not just efficiency or technology, drive public acceptance
Reversibility design: Curb lanes, loading zones can be repurposed incrementally; full commitment not required upfront

Sources:

Case 3: London CS11 Cycle Superhighway (Contested Pilot)

Project Overview

Route: East-West cycle corridor through central London (Westminster, Camden)
Scope: Protected cycle lanes, segregated from traffic
Timeline: Consulted 2016; scheduled construction 2018; indefinitely on hold as of 2024

Pilot Status & Opposition

Consultation (2016): 60% of respondents supported the scheme
Opposition: Westminster Council opposed; Camden qualified support with reservations
Petition objections: 3,873 objections lodged by petition; not counted in TfL’s official consultation summary
Legal challenge: Westminster sued TfL; courts refused TfL’s appeal in ~2019–2020
Current status: Project indefinitely on hold (no pilot ever conducted)

Relevant Data (from Broader Cycle Superhighway Studies)

Other CS routes: Significant increase in cycle hire usage in effect areas
- Docking stations within effect area: +27.1% average ridership increase
- Trips with both origin/destination in effect area: +73.2% increase
Safety outcomes: London cycle superhighways associated with reduced collision rates

Why This Case Matters (Negative Example)

No reversible pilot: Project moved to consultation→plan without low-cost temporary trial
Opposition crystallized early: Lack of reversible pilot meant opposition framed as principle-based, not evidence-based
Legal vulnerability: Opponents used legal process to block; no trial data to defend design
Lessons: Temporary painted pilots before full buildout would have:
1. Allowed Westminster to test claims before permanent decision
2. Provided empirical evidence to counter speculation
3. Reduced perceived irreversibility (key fear driver)
4. Given Westminster & TfL common ground for compromise

Application to CAM Governance

Do not skip pilots: Announcing full CAM infrastructure plans before temporary trials risks opposition crystallizing around principle
Reversibility signals: Paint, lightweight bollards, or temporary lane markings cost <10% of permanent infrastructure but signal flexibility
Stakeholder engagement: Local government stakeholders (Westminster analogue) must have input into pilot design, not just deployment plans
Evidence collection: Pilot allows empirical collection of data to address opposition claims (safety, traffic, access)

Sources:

Case 4: NYC Protected Bike Lanes (Post-Sadik-Khan Expansion)

Expansion Under Sadik-Khan (2007–2013)

Total bike lanes installed: Nearly 400 miles system-wide
Protected lanes: 120 miles (193 km) of protected/separated bike lanes installed
Notable pilot: 9th Avenue protected bike lane (early high-profile installation)

Measured Outcomes (9th Avenue Pilot & Broader System)

Safety: 47% reduction in injuries to all road users on 9th Avenue post-installation
Economic: 49% increase in retail sales on 9th Avenue after bike lane introduction
Ridership: >2x growth in bike share usage since 2007 infrastructure buildout
Public support: 66% of New Yorkers support bike lanes (2010s baseline)

Post-Sadik-Khan Expansion

De Blasio administration (2014–2019): Continued acceleration of protected lane installation
Adams administration (2020–present): Pace of expansion declined; political headwinds from truck operators, some merchants

Governance Mechanism (Why Scaling Succeeded)

Early high-profile pilots: 9th Avenue protected lane became proof-of-concept; data collection built confidence
Measurable outcomes: Safety (47% injury reduction) and economic data (49% retail sales increase) provided strong political justification for city-wide rollout
Incrementalism: Lanes added neighborhood by neighborhood, not in one comprehensive plan; easier to manage opposition
Persistence through administrations: Despite initial opposition, safety data and ridership growth made reversing lanes politically costly
Equity framing: Lanes connected to broader mobility justice and street safety agenda, not just cycling enthusiasm

Scaling Conditions

Pilot-first, then rollout: 9th Avenue success preceded city-wide plan
Continuous measurement: Quarterly reports on safety, usage, and economics maintained political support
Incremental geography: New lanes by neighborhood; not city-wide mandate
Labor/merchant engagement: Early outreach to truck operators and merchants addressed concerns; not all resolved, but managed

Challenges (Post-Scaling)

Merchant opposition: Some merchants blamed lane reduction for street access losses (contested by TfL data)
Truck driver opposition: Lanes reduced commercial vehicle movement; unions resisted
Political susceptibility: Adams administration reversed some lanes due to pressure; suggests lack of deep political consensus (unlike Oslo, Barcelona)

Application to CAM Governance

Pilot early, communicate results: 9th Avenue pilot + published safety data allowed confidence-building before city-wide rollout
Incrementalism matters: Neighborhood-by-neighborhood approach is less politically contentious than city-wide plan
Vulnerable to reversal: Without strong equity/health mandate (like Barcelona), infrastructure can be reversed if new political opposition emerges
Labor & merchant engagement: CAM governance must address impact on parking attendants, delivery businesses, transportation workers; not ignore these constituencies

Sources:

Key Takeaway for Ch.8

Reversible pilots with clear success metrics scale better than imposed mandates. Oslo (28% traffic reduction, 75% support), Barcelona (700 deaths/year prevented, expanding to 500 blocks), and NYC 9th Avenue (47% injury reduction, 49% retail growth) all scaled because pilots generated credible outcome data. CS11 in London stalled because it skipped the reversible pilot phase, allowing opposition to crystallize around principle. CAM governance should require temporary pilots with specific metrics (e.g., “If CAM market share reaches X%, permanent curb reallocation will proceed”) before infrastructure commitment.

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