Despite millions of dollars spent on improvements to ensure bicyclists and motorists better coexist on the Redondo Beach waterfront, some are predicting disaster by the Fourth of July.

Critics of the Redondo Harbor Gateway and Bike Path Improvement Project — a new bike path along Harbor Drive and lane changes on Herondo Street — emerged even before it was officially unveiled last week.

The cinching of Herondo down to one lane and the installation of wide, two-way bike and pedestrian lanes along the west side of Harbor Drive — already dotted with busy driveways and parking lot entrances — better connects bicyclists from Redondo Beach to The Strand in Hermosa Beach through what was formerly a city parking lot.

The city knocked down the wall that had separated Redondo’s northern border from The Strand last fall and developed a small public plaza as part of the $4.6 million project.

Biking enthusiasts have lauded the project for improving safety for bicyclists and hopefully attracting the public down to the harbor and pier area.

But making way for the bike path meant narrowing Herondo Street and adding sharrows, or shared-lane markings, to Harbor Drive.

And for many, the changes haven’t been well received.

Residents have flooded social media over the last couple weeks with comments on the new streetscape, posting photos of traffic backups and cars parked the wrong way in the new back-in angled parking along Herondo.

Local Realtor Chris Prenter posted a photo of an evening backup on Herondo heading east toward Pacific Coast Highway on the “Hermosa Beach Forum” Facebook page, writing, “Herondo as a single lane is a fail. How many light cycles does it take to get across PCH?” Three, he said.

The post has garnered 115 comments.

“Wow, just lunacy this design. And I understand the plan is to have people back into those spots for beach parking??!! WTF??” wrote John Valencia.

“I’m an attorney and I can tell you that reverse-angle backup parking will make me extra work. What a stupid idea. Whoever thought of it should be fired,” wrote Joseph Di Monda.

In another Facebook post, a woman wrote, “25 cars lined up on Herondo to cross PCH. The nightmare begins.”

In an interview, Di Monda, a Manhattan Beach attorney, said he has been biking in the South Bay since the 1980s. His Saturday routine is a bike ride from Torrance Beach to Marina del Rey or Santa Monica.

“The location of the new bike path, the interruption of all the parking lots, makes me nervous riding a bike now,” he said. “I’m constantly watching traffic to make sure they’re paying attention to me as well as me paying attention to them. I think they have increased the likelihood of bicycle/auto accidents because of the way it’s designed.”

Di Monda questioned if the city had other options, such as putting the bike lane on the east side of Harbor Drive along the AES power plant, a long stretch of road with no parking lot entrances.

As for Herondo, Di Monda said that despite the city’s claim that it has now fixed the timing of the light at PCH, there simply are too many cars in the area for one lane each way, no matter the light schedule. That, paired with the new back-in parking, is “very problematic,” he said.

“I don’t want to be the guy stopping progress, but I just wonder, ‘Did they think everything through?’ ” he said.

Nick Walden, the King Harbor Marina coordinator who staffs the parking booth off Marina Way for Bluewater Grill and Bay Club Redondo Beach, among other businesses, five days a week, has been watching traffic up and down Harbor Drive and the surrounding streets for five years.

With the changes, some drivers, especially the elderly, have now been turning right onto Harbor Drive off Marina Way and onto the bike path, previously the right lane, he said. Or people drive down the center turn lane.

“Everyone is turning right into the bike lane,” he said. “It’s pretty bad. Having the bike lane on this side of the street was not wise.”

As if planned, just minutes later, a woman attempting to turn onto Harbor Drive from Beryl Street turned into the bike lane, to the shock of bikers and in-line skaters nearby. The woman realized her mistake and frantically steered her way back into a driving lane.

But what’s worse is Herondo, Walden said, especially at rush hour.

“Going east on Herondo toward PCH is just a nightmare sometimes,” he said. “Even during light rush-hour traffic, you have to go through two light cycles just to get across PCH. It’s not practical. I don’t understand why there’s only one lane now.”

A parking attendant at the Redondo Beach Marina parking lot near Captain Kidd’s said he consistently sees bicyclists, skateboarders and the like zooming past the entrance, not obeying the stop signs, or perhaps not caring. Others have similar complaints, and say Harbor Drive backs up with cars, as those waiting to turn right are unable to because of bicyclists not following the rules.

“I’ve seen a lot of close calls here,” said the attendant, who declined to give his name. “There needs to be police staffed here full time or more signage. The bicyclists just don’t stop.”

City staffers and City Council members have chimed in on social media, telling residents that the improvements still need tweaking and time for adjustment. The city’s engineering department did not return phone calls.

“I’ve been riding my bike along Harbor Drive from Redondo to Hermosa since 1968, and I can assure everyone that what is there now is much safer than what was there before,” Councilman Bill Brand said. “Are there some changes that need to be made? Absolutely. … It’s not a finished product yet.”

Brand said the council members will take all of the feedback they’ve received, through social media, calls and emails, and work with city staff to make changes if necessary. The back-in parking could be restriped for front angle, he said.

“I don’t know what’s quite the answer,” he said. “The traffic engineer is looking at all this. There’s still work to be done.”

Walden just hopes the dust settles in the next two weeks.

“Wait ’til July 4,” he said. “I don’t even want to see what happens that day. That will be the true test of this new infrastructure.”