Government Street may be going on a “road diet,” but now it appears that one section will remain four lanes instead of slimming to three.

Local and state officials have been talking for years about winnowing the road down from two lanes in either direction to a single lane each way with a center turning lane and bike lanes. It is an attempt to make the corridor more accessible for bicyclists and pedestrians, and city leaders hope it will spur retail growth.

In 2014, East Baton Rouge Parish Mayor-President Kip Holden said he expected the project to be complete by 2015. Recently, city and state officials gave differing estimates for when work actually will begin, but it could be late 2019 before a slimmed-down Government Street opens to traffic.

In fact, plans have changed since the project began more than two years ago. The original design called for the road diet to run between East Boulevard by Interstate 110 to Lobdell Avenue near Independence Park.

But road diets aren’t the right design for every corridor. Federal studies show that once a street serves about 20,000 vehicles per day, road diets cause so much congestion drivers have to begin taking alternate routes.

On Government Street, more than 25,000 vehicles drive the stretch near Baton Rouge Community College every day, according to a 2015 study commissioned by the state Department of Transportation and Development.

Asked about the traffic load, East Baton Rouge Parish transportation and drainage director Stephen Bonnette emphasized the initial designs for Government Street predate his tenure with the city.

Bonnette said he was aware of the federal studies and brought his concerns to the state. Now, he said, it’s his understanding that the stretch of Government between South Foster Drive and Jefferson Highway will remain as it is now, with four lanes.

That means Government will trim to three lanes, then swell back to four, then reduce back to three.

One federal expert said switching back and forth “can be problematic.”

“Generally, it’s not recommended,” said Mark Doctor, a safety and design engineer at the Federal Highway Administration. The concern is that drivers may try to make quick, possibly dangerous lane changes in the short stretch where passing is possible.

But Bonnette said while that kind of lane change generally may be a safety concern, engineers who have studied Government Street believe the design is appropriate because so many drivers turn off at Jefferson Highway.

Moreover, the DOTD study found Government Street’s daily traffic load is higher than the federal recommendation for a three-lane roadway as far west as Acadian Thruway. The numbers aren’t quite as high — 20,790 vehicles per day between Acadian and Foster — but traffic volume is expected to increase over time.

A road diet may slow down vehicle drive times in exchange for easier bicycle and pedestrian traffic or improved safety, Doctor said, which “may be a very reasonable trade-off.”

DOTD Communications Director Rodney Mallett said engineers have modeled the proposed road diet and found that introducing a center lane will make driving safer.

Proponents of the road diet have pointed to safety as one of the primary reasons for the switch, saying three lanes create fewer potential points where a crash can occur.

Researchers have been all over the map on the safety of road diets.

A 2004 Federal Highway Administration paper remarked that they “likely would reduce total crashes by 6 percent or less. Road diets were no better or worse than comparison sites with regard to crash severity.” However, two years ago, the FHA reviewed several studies and concluded that “studies indicate a 19 to 47 percent reduction in overall crashes.” Another publication indicates that rural areas saw a greater decline in crashes than suburbs and cities.

Highway administration spokesman Neil Gaffney said road diets have been implemented or planned in 40 states, and one northern Virginia road diet reduced crashes 67 percent.

DOTD has claimed the Government Street overhaul will lead to a 52 percent reduction in crashes. The overall project includes both the road diet and the installation of a traffic circle to replace the lighted intersection at Lobdell Avenue, where Government becomes Independence Boulevard. Traffic circles function similarly to roundabouts, which DOTD officials have said are safer than stoplights.

Doctor also praised roundabouts for their increased safety and said they work well with road diets to regulate traffic flow.

However often crashes occur, the new design with its center lane should allow ambulances and other emergency vehicles to move more quickly, Bonnette said.

On the other hand, buses pose a dilemma.

Officials haven’t presented any plans for getting city buses out of traffic when they need to pick up or drop off a rider. At a community meeting in December to discuss plans for a Government Street road diet, several attendees submitted questions about the issue.

“The DOTD project team evaluated bus turnouts along Government Street, but we found them to be cost prohibitive due to the required right-of-way purchase,” the department wrote in a typical response.

“DOTD is currently seeking partnerships with private investors and businesses to provide servitudes to use for bus turnout alternatives. Following the implementation of the project, (the Capital Area Transit System) will re-evaluate the number of stops on Government Street because walkability would be improved.”

CATS spokeswoman Amie McNaylor said transit officials asked DOTD about bus stops and bike lanes in December, but the two agencies haven’t spoken since.

Buses are not legally allowed to stop in bike lanes, Bonnette said.

“I think (bus stops are) still a problem that we and CATS will need to address,” he said.

While some residents have expressed reservations about the road diet, others are excited. Holden has said he wants the corridor to attract more bicyclists and pedestrians. He has imagined a Government Street that resembles Magazine Street in New Orleans, with lots of shops that people can walk to.

However, the mayor’s original assertion that the work would be completed by 2015 hasn’t panned out. His chief administrative assistant, William Daniel, said DOTD has slowed down the process.

“They’ve been studying it and studying it and studying it,” he said recently.

DOTD officials disagree.

“There hasn’t been a holdup on this project. It’s funded with federal and state funds, so standard procedures, guidelines, and time frames need to be followed,” spokesman Bill Grass wrote in an email.

State officials have previously pointed out that Government Street runs through several historic districts or by historic buildings, and the state has to make sure they aren’t affected by construction.

Even now, it’s not clear when the project will break ground.

Various city and state authorities indicated that the project will be ready to go to bid or begin construction sometime within the next year or two.

Mallet said the bids won’t go out until next spring, meaning construction will start sometime before the end of 2017 and will take two years to finish.

Follow Steve Hardy on Twitter, @SteveRHardy.