New report tackles a pollution puzzle: while other pollutants drop on weekends, smog-causing ozone levels actually increase over the weekend in certain parts of California.
In the Los Angeles area, ozone levels typically are 32 percent higher on Saturdays and Sundays than they are Monday through Friday when freeways are clogged with commuters. The difference is 25percent in San Francisco. The phenomenon in Los Angeles and San Francisco, first noticed in the 1980s, has four possible explanations, according to the report.
Thanks to Abhijeet Chavan
FULL STORY: Report cites several reasons for weekend smog increase

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

Chicago’s Ghost Rails
Just beneath the surface of the modern city lie the remnants of its expansive early 20th-century streetcar system.

Amtrak Cutting Jobs, Funding to High-Speed Rail
The agency plans to cut 10 percent of its workforce and has confirmed it will not fund new high-speed rail projects.

Ohio Forces Data Centers to Prepay for Power
Utilities are calling on states to hold data center operators responsible for new energy demands to prevent leaving consumers on the hook for their bills.

MARTA CEO Steps Down Amid Citizenship Concerns
MARTA’s board announced Thursday that its chief, who is from Canada, is resigning due to questions about his immigration status.

Silicon Valley ‘Bike Superhighway’ Awarded $14M State Grant
A Caltrans grant brings the 10-mile Central Bikeway project connecting Santa Clara and East San Jose closer to fruition.
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