By Shawn Cohen, Rebecca Harshbarger, Lia Eustachewich and Laura Italiano
September 20, 2014 | 2:00am
Seconds before he plowed his $4,000 bike into Connecticut mom in Central Park, leaving her brain dead, speed-demon racing cyclist Jason Marshall zoomed down a pedestrian lane and crossed over into the vehicle lane of the park’s West Drive — even though neither is legal for cycling, The Post has learned.
Law-enforcement sources say that moments before Thursday afternoon’s accident, Marshall was barreling downhill in the lane restricted to pedestrians and child bicyclists.
Somewhere in the West mid-60s, he swerved to avoid a pedestrian, then kept going on a diagonal, veering out of the pedestrian lanes and crossing the central bike lane before swinging into the vehicle lane.
Just then, as he approached the traffic light at West 63rd Street, Jill Tarlov, 58, was stepping off the curb.
Tarlov, of Fairfield, remains on a ventilator at New York-Presbyterian/Weill Cornell Medical Center. The former 1010 WINS exec has been married for nearly three decades to Michael Wittman, a senior vice president at CBS. They have two college-age children, Matthew and Anna.
Marshall, a studio session saxophonist, told cops he couldn’t say how fast he was pedaling down the park’s West Drive when he slammed into Tarlov, source said.
“We don’t know how fast he was going,” one frustrated investigator conceded Friday night.
But Marshall, 31, of East Harlem, likes to go very fast — and boasts about it online almost every day.
He uses a GPS and other software to track his maximum and average speeds during his often twice-daily rides through the park, The Post has found.
His blazing speeds are uploaded — precise to the 10th of a mile per hour — onto a competitive running and cycling Web site.
“New Chain, brakes and RD(7800gs),” he had boasted earlier Thursday on the Strava site, referring to a new rear derailleur for his bike. “All systems go.”
Hours before he slammed into Tarlov, Marshall had logged 32.2 miles of cycling during a predawn spin through the park, the site says — and listed his top speed for that ride at 35.6 mph, well over the 25 mph speed limit for bikes and cars.
His maximum speed during five sprints on that same downhill stretch of West Drive during his Thursday-morning ride was 28.9 mph, his data on Strava says.
Marshall — who appeared to have logged every one of his 9,000 miles ridden so far this year — left no record of the one afternoon ride that put Tarlov in the hospital.
He declined to comment Friday as he left his East 120th Street apartment on the way to his Upper East Side lawyer’s office.
After the crash, he admitted to cops he was in the wrong lane but insisted he wasn’t speeding, had the green light and had shouted to warn Tarlov as he approached, law-enforcement sources said.
But so far, witnesses have told cops that Marshall appeared to be going at a high rate of speed and had tried to swerve rather than brake.
He had not been charged as of Friday night. Depending on what police find, and on Tarlov’s precarious status, he could face anywhere from a summons for cycling in the wrong lane to charges of assault or reckless homicide, sources said.
For now, Marshall is off his wheels, his bicycle, a yellow-and-black Jamis Eclipse, confiscated as evidence by the police.
Additional reporting by Larry Celona, Ben Feuerherd and Elizabeth Hagen