According to Jim Titus, two federal government agencies will withdraw their claims that bike helmets are "85% effective".

Titus writes that "(t)he decision comes in response to a petition the Washington Area Bicyclists Association (WABA) filed under the federal Data Quality Act". The group is not anti-bike helmet, having "started the Bicycle Helmet Safety Institute, an independently-funded organization that reviews bicycle helmets and encourages improvements in their design." However, they do not support mandatory helmet laws for adults.
Titus points to a "1989 study in Seattle estimated that helmets prevent 85% of head injuries. Later efforts to replicate those results found a weaker connection between helmets and head injuries, but public health advocates, government web sites, and the news media often present it as fact."
From: "A case-control study of the effectiveness of bicycle safety helmets"; Thompson, Rivara & Thompson, New England Journal of Medicine, 1989:
Safety helmets are widely recommended for cyclists, but convincing evidence of their effectiveness is lacking. Over one year we conducted a case-control study.....We conclude that bicycle safety helmets are highly effective in preventing head injury. Helmets are particularly important for children, since they suffer the majority of serious head injuries from bicycling accidents.
While the degree of safety offered by bike helmets may be up for debate, what isn't is the prevalence of head injuries caused by cycling, writes Anahad O'Connor in a June 3, New York Times article, "Really? Cycling Is the Top Sport for Head Injuries".
Titus writes that since 1989, additional studies "found that helmets reduce the risk of head injuries, but less frequently than Thompson's team found. Some studies even found that helmets increase the risk of neck injuries."
WABA "requires helmets on all rides that it organizes." However, they "draw the line at laws requiring adults to wear helmets. Such laws do little to promote safety, but they discourage bike sharing and other uses of bicycles for short trips", according to Titus.
In WASHCYCLE, Titus identifies one of the federal agencies: the National Highway Traffic Safety Administration (NHTSA) that "is withdrawing its long-standing claim that bicycle helmets prevent 85% of head injuries".
From NHTSA's Bicycle Riding Goal #3: Bicyclist Shall Wear Helmets: "Bicycle helmets are 88% effective in preventing serious brain injury."
FULL STORY: Feds will stop hyping effectiveness of bike helmets

Trump Administration Could Effectively End Housing Voucher Program
Federal officials are eyeing major cuts to the Section 8 program that helps millions of low-income households pay rent.

Planetizen Federal Action Tracker
A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

Canada vs. Kamala: Whose Liberal Housing Platform Comes Out on Top?
As Canada votes for a new Prime Minister, what can America learn from the leading liberal candidate of its neighbor to the north?

Washington State’s Parking Reform Law Could Unlock ‘Countless’ Acres for New Housing
A law that limits how much parking cities can require for residential amd commercial developments could lead to a construction boom.

Wildlife Rebounds After the Eaton Fire
Following the devastation of the Eaton Fire, the return of wildlife and the regrowth of native plants are offering powerful signs of resilience and renewal.

LA to Replace Inglewood Light Rail Project With Bus Shuttles
LA Metro says the change is in response to community engagement and that the new design will be ready before the 2028 Olympic Games.
Urban Design for Planners 1: Software Tools
This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.
Planning for Universal Design
Learn the tools for implementing Universal Design in planning regulations.
Central Transportation Planning Staff/Boston Region MPO
Heyer Gruel & Associates PA
Institute for Housing and Urban Development Studies (IHS)
City of Grandview
Harvard GSD Executive Education
Regional Transportation Commission of Southern Nevada
Toledo-Lucas County Plan Commissions