Does It Work?

No published, peer-reviewed evaluation of a specific named clean team program has been identified in the research literature. The 2024 systematic review in Crime Prevention and Community Safety, which examined every quantitative study of BID effects on crime, acknowledged that “the tactics adopted by each BID area are complex and not easy to approximate in a statistical model” — and even that review examined BIDs generally, not clean teams specifically. Three bodies of adjacent research are cited in clean team policy discussions. None studied a clean team directly.

Environmental Remediation Reduces Crime

A 2018 cluster randomized controlled trial led by Charles Branas at the University of Pennsylvania, published in the Proceedings of the National Academy of Sciences, randomly assigned 541 vacant lots across 110 clusters in Philadelphia to receive simple environmental remediation: trash removal, mowing, basic greening with low fences and plantings. Control lots received nothing.

Treated lots saw a 29 percent reduction in gun violence and a 22 percent decrease in burglaries. Nuisance complaints dropped 30 percent. In neighborhoods below the poverty line, the violence reductions were even larger. Residents living near treated lots reported feeling substantially safer: fear of crime dropped 37 percent and safety concerns fell 58 percent. More than three-quarters said they spent more time outdoors after remediation. The intervention cost roughly $5 per square foot. The mechanism the researchers identified was increased use of public space: when vacant lots looked maintained, people used them, and that human presence displaced the conditions that enable crime (Branas et al., PNAS 2018).

Whether these results transfer from vacant lot remediation in residential Philadelphia neighborhoods to commercial corridor maintenance in cities with different demographics, density, and disorder patterns has not been tested directly.

BID-Funded Programs Reduce Crime

A 2024 systematic review published in Crime Prevention and Community Safety examined the full body of quantitative research on Business Improvement Districts. Of nine quantitative studies examined, eight found statistically significant crime reductions associated with BID operations. All six studies that measured property crime specifically found significant reductions. Displacement was rare: crime did not simply move to adjacent areas (BID systematic review, Crime Prevention and Community Safety, 2024).

Earlier individual studies provide more specificity. Leah Brooks at George Washington University found that Los Angeles BIDs reduced crime by 5 to 9 percent, at a cost of approximately $21,000 per violent crime averted, compared to the estimated $57,000 social cost per violent crime (Brooks, GWU). John MacDonald at the University of Pennsylvania and colleagues found that BIDs in Los Angeles produced robbery reductions of 12 percent annually, with estimated savings ($757,611) nearly equal to the BID budgets that produced them ($736,670) (MacDonald et al., UPenn).

These studies measured the combined effect of everything BIDs do — cleaning, ambassador presence, marketing, streetscape improvements, and business development. The systematic review noted that isolating individual components is not possible in the existing research.

Transitional Employment Reduces Recidivism

A 2012 randomized controlled trial conducted by MDRC, a nonprofit research organization, evaluating the Center for Employment Opportunities, tested whether transitional employment in cleaning and maintenance work reduced criminal justice involvement for formerly incarcerated individuals. The study enrolled 977 participants.

People assigned to the transitional employment program showed a 22 percent reduction in recidivism for recently released participants, with first-year reductions up to 26 percent. Employment gains faded after the transitional period ended, but the recidivism reductions persisted. MDRC calculated net benefits of $4,900 per participant (MDRC, 2012). A separate RTI International/REDF evaluation (July 2021) of Central City Concern’s social enterprises, including Clean Start, found a $1.98 return on investment for every dollar spent (RTI/REDF, 2021; centralcityconcern.org).

Programs like Cincinnati’s GeneroCity 513, Portland’s Clean Start, Portland’s GLITTER, and Kansas City’s Clean Up KC operate on this model. Whether any specific workforce-development clean team produces comparable results to the CEO trial has not been independently tested.

The Broken Windows Update

The intellectual foundation for environmental maintenance as a public safety strategy traces to the broken windows hypothesis. A 2024 meta-analysis by Anthony Braga, Christopher Schnell, and Brandon Welsh, synthesizing 56 studies, found a distinction documented across the literature: community-based, problem-solving interventions that change the physical and social environment produced crime reductions. Aggressive order-maintenance enforcement, including zero-tolerance policing and misdemeanor arrest campaigns, did not produce statistically significant crime reductions (Braga, Schnell, and Welsh, Criminology & Public Policy, 2024).

Program-Reported Data

The evidence that follows is reported by programs or cities, not independently verified by researchers.

Seattle MID: Since 2013, more than 10 million gallons of trash and 94,000 syringes collected across 300 blocks. The MID renewed its authorization for 10 years in May 2023 with an $18 million annual budget (DSA 2024 annual report). Workers administered roughly 300 Narcan doses in 2023 alone (KING5). No independent evaluation of crime or safety outcomes has been published.

Cincinnati GeneroCity 513: Joe Rudemiller, vice president of marketing and communications at 3CDC, told WCPO that the program produced documented results in its first year: “Cleaning 674 miles worth of streets, filling 5,566 bags of trash, paying out $70,155, connecting 125 [people] to other social services for assistance, linking 34 people with permanent housing; and helping 18 people get permanent employment” (WCPO, September 2019). Through September 2025, the program had logged 2,648 encounters and 376 intakes (3CDC program data).

Portland Clean Start: Central City Concern removed 6.02 million pounds of trash and 92,150 syringes in 2024 with more than 130 employees and 60-plus vehicles. Central City Concern reports that participants are seven times more likely to complete treatment than comparable populations. That is a program-reported figure for a self-selected population, and the comparison methodology has not been published (CCC program page; CCC Cleaners of the Year, 2024).

Portland GLITTER: The Ground Score Association reports that approximately 90 percent of its roughly 47 payroll employees were currently or formerly homeless at hire, and more than 70 percent of participants who were tent-dwellers have moved into permanent housing. Earlier program reports cited 63 employees, 95 percent formerly homeless, and 83 percent housed; those figures reflected a late-2024 peak before staffing contracted (Ground Score, 2025; City of Portland, November 2024).

Portland, Maine needle buyback: Launched January 2025 with $52,000 in opioid settlement funds. In the six weeks after launch, the city collected 120,793 syringes, compared to 76,554 in the six weeks before — a 52 percent increase. By year-end 2025, the syringe return rate reached 86 percent, up from 66 percent the prior year (Maine Wire, March 2025; NEWS CENTER Maine, February 2026; Press Herald, February 2026).

Boston Community Syringe Redemption: Over its three-and-a-half-year life (December 2020 to June 2024), the program collected 5.2 million syringes, enrolled 3,738 participants, and distributed 3,781 doses of naloxone at a buyback rate of $0.20 per syringe. At peak, the program was responsible for 80 percent of the city’s needle collection volume some months. After its American Rescue Plan Act (ARPA) funding expired and the city chose not to replace it, 311 needle complaints roughly doubled (Boston Globe, July 2024; Boston Globe, January 2025; ARR program page).

Lacey, Washington: The Rapid Response Team, in its first year, collected 341 hypodermic needles, removed more than 12 tons of debris from public spaces, recovered 333 shopping carts, and cleaned 46 graffiti-tagged sites. Two team members were recognized for reviving a man suspected of overdosing (The Olympian, via Clean Teams Newsletter).

Portland, Oregon TriMet: TriMet’s Clean Team crews broke an annual record in 2025, engaging in cleanups on the public transit system “more than 100,000 times,” working seven days a week removing “trash, graffiti, spills… pressure-washing platforms and cleaning trains throughout the day” (TriMet News, via Clean Teams Newsletter).

The Syringe Services Evidence Base

A CDC synthesis drawing on 30 years of research found that syringe service programs reduce HIV and hepatitis C incidence by approximately 50 percent, do not increase drug use or crime in surrounding areas, and connect users to treatment at five times the rate of non-participants (CDC SSP synthesis). A Veterans Affairs systematic review found that SSP users are 2.3 to 5.8 times more likely to dispose of syringes safely than non-participants (VA HSR&D systematic review). No published evidence supports the concern that syringe programs increase community needle litter. Needlestick HIV transmission from discarded community needles is classified as extremely unlikely by infectious disease researchers, with no confirmed cases in the published literature (CDC).

This evidence evaluates syringe service programs broadly, not clean team syringe collection specifically. Portland, Maine’s 52 percent increase in syringe collection after implementing a buyback program, combined with the 86 percent year-end return rate, provides a documented before-and-after comparison for syringe collection specifically (Maine Wire, March 2025; NEWS CENTER Maine, February 2026).

Leslie Collins, president of Scranton Tomorrow, which oversees a clean team in Scranton, Pennsylvania, described the dynamic from the operational side: “The physical appearance of downtown plays a significant role in how people perceive the district in its entirety, its economic stability, and opportunities for future growth” (Discover NEPA, via Clean Teams Newsletter).

What the Evidence Does Not Cover

No clean team program has been independently evaluated. Seattle’s MID has operated since 2013 without a published evaluation of its impact on crime, fear, or safety. Portland’s Clean Start, Cincinnati’s GeneroCity 513, and every other program described in this product report their own data without independent verification.

The transfer from vacant lot remediation to street-level maintenance has not been tested. Branas studied vacant lots in residential Philadelphia neighborhoods. Whether comparable results apply to commercial corridor cleaning in Seattle, syringe collection in Portland, or workforce development cleaning in Cincinnati is unknown. The scale, context, population, and physical environment differ (Branas et al., 2018).

The BID research measures the combined effect of cleaning, ambassador patrols, streetscape improvements, and business development. No study has isolated the cleaning component. The systematic review acknowledged this limitation directly: studies “are complex and not easy to approximate in a statistical model” (BID systematic review, 2024).

Workforce development outcomes describe results for the workers, not the neighborhoods. The MDRC trial measured whether transitional employment reduced recidivism for participants. It did not measure whether the neighborhoods where participants worked became safer. Those are different research questions (MDRC, 2012).

No research provides dosage guidance — how much cleaning produces a safety effect, how frequently graffiti must be removed, or what service level is required to produce the results the adjacent evidence documents.

Public opinion data shows broad support for the concept. Safer Cities national polling found 84 percent of respondents support “picking up needles and other drug paraphernalia to ensure public spaces are safe and clean” (Safer Cities national survey, Q&A). In Harris County, Texas, 83 percent of residents said clean team units would be “effective” at “making Harris County safer” (Harris County polling, Q&A). These are measures of public sentiment, not program effectiveness — they tell a decision-maker that the political environment is favorable, not that the programs produce specific outcomes.

San Francisco’s 2025 city performance audit documented the gap between spending and measurable outcomes. The city spends approximately $60 per resident on street cleaning — roughly twice the Los Angeles rate — but the Budget and Legislative Analyst found $15.2 million unspent and $3 million in illegal dumping fines uncollected, and concluded that the Department of Public Works does not track spending “in a meaningful way” (SF BLA audit, 2025; Mission Local, October 2025). The audit found the city lacked metrics connecting inputs to outcomes (SF BLA audit, 2025).

The Bottom Line

Three bodies of adjacent research document the mechanisms clean teams use: environmental remediation reduces gun violence by 29 percent in a randomized controlled trial (Branas et al., 2018); BID operations reduce crime in eight of nine quantitative studies (BID systematic review, 2024); transitional maintenance employment reduces recidivism by 22 percent in a randomized controlled trial (MDRC, 2012); and community-based environmental interventions outperform enforcement-based approaches across 56 studies (Braga, Schnell, and Welsh, 2024). Every clean team outcome cited in this product is self-reported by the program that produced it. For cities spending $18 million (Seattle) to $32 million (San Francisco) annually, no controlled evaluation of any operating clean team has been published.