Almost exactly two years ago, hundreds of cyclists and mourners gathered on the Rickenbacker Causeway to plead for improved road safety after a husband and father was mowed down by a hit-and-run driver while out on a morning ride on Miami-Dade County’s most popular recreational bicycling route.

On Saturday morning, hundreds of cyclists from across the county rode to a different spot on the causeway — on the big bridge leading to Virginia Key. They mourned yet another husband and father fatally struck by a hit-and-run driver, but this time with greater urgency and a tinge of anger at authorities they contend have not done enough to curb speeding motorists and improve safety on the Rickenbacker.

“It’s an epidemic with cars hitting bikers out there,’’ said Ricky Arriola, a business executive and triathlete who trains on the causeway’s marked bicycle lane early in the morning several times a week, just like the victim in Wednesday’s hit-and-run, 36-year-old Aaron Cohen, did. “But I never see a cop out there. We need to have some sanity here.’’

Cyclists say nonfatal collisions and near-misses have increased as more people turn to the Rickenbacker and its wide, designated bike lanes and multi-use pathways, especially on the highway-like portion connecting the Miami mainland to Key Biscayne.

While advocates concede that some reckless cyclists put themselves at risk, they contend that most drivers on the causeway exceed the speed limits of 40 and 45 miles an hour, often just inches from pedaling cyclists in the bike lanes, endangering not just people on bikes but also the runners and pedestrians who flock to the causeway.

Some advocates are calling for a greater police presence to deter speeders and catch drunken drivers.Some critics also blame the roadway design, which they say is unsuitable for sharing between fast-moving vehicles and people on bicycles. But they complain that calls for traffic-calming measures such as lower speed limits and safety barriers or greater separation between bike and auto lanes after the January 2010 death of Christophe LeCanne went unheeded by county officials who have jurisdiction over the causeway.

The county’s assistant chief of traffic engineering, Jeff Cohen, said Friday that substantial improvements are in the planning stage.

“We’re looking at everything,’’ Cohen said. “This hurts me, too, and I promise you, there will be results.’’

But the problem is not limited to the Rickenbacker, some advocates say.

“We’re concerned about the culture of entitlement that a lot of drivers in Miami seem to represent, an attitude of get out of my way and I have a God-given right to go as fast as I want to go,’’ said Hank Sanchez-Resnik, a Key Biscayne resident and co-founder of Green Mobility Network, a cycling advocacy group that on Friday announced the launch of a safe-streets campaign in the aftermath of Aaron Cohen’s death.A Key Biscayne resident, Michele Traverso, 25, was jailed Friday, two days after police tracked down his badly damaged Honda Civic to the garage of his condo on Grapetree Drive in Key Biscayne. Police initially charged Traverso with leaving the scene of an accident with bodily injury and driving with a suspended license. He was then sentenced to 21 days in jail for violating probation on a 2009 conviction for marijuana possession. Additional charges may result from Cohen’s death.

Coincidentally, Traverso’s condo complex was also home to Carlos Bertonatti, charged in the January 2010 hit-and-run death of cyclist Christophe LeCanne on the Rickenbacker’s Bear Cut bridge bike lane.

Wednesday morning bike rides were a ritual for Cohen, a competitive triathlete, and friend Enda Walsh. They would meet at the causeway entrance at 5:30 a.m. so that Cohen, sales manager at Esserman International Acura in Doral, could return to his home in the nearby Roads neighborhood to take care of his two children, Lily, 3 and Aiden, 14 months, when his wife, Patty, left for work.

The two cyclists — both their bikes equipped with front and rear lights — were climbing the Powell bridge toward Virginia Key when they were struck from behind, Walsh said. While Walsh escaped with a broken leg, Cohen — who appears to have been thrown over the top of the Honda Civic that struck them — suffered a fatal head injury.

Those who knew him say Cohen was a warm, kind and caring man who made friends of co-workers and customers.

“He was one of those rare individuals that happen a handful of times in anybody’s lifetime,” said Eddie Lopez, Cohen’s supervisor.