After wrapping up a public-comment period in an ambitious Chicago bus project, Mayor Rahm Emanuel’s administration faces tough choices about the design.

The city can stick to its plans and push for federal funds to build what would be the nation’s most advanced “bus rapid transit” line. The project would transform Ashland Avenue, beginning with a 5.4-mile leg that would connect several passenger rail lines before they reach the Loop and, planners say, spur economic development that benefits the entire Chicago region.

But there could be significant collateral damage, especially to the trucking operations of companies in an historic industrial corridor along the route.

The Chicago Transit Authority says the BRT line, which could eventually lengthen to 16 miles, would cut the average Ashland bus ride time roughly in half. But some companies in the Kinzie Industrial Corridor and a few large retailers nearby say they would struggle too much to make and receive deliveries and keep customers flowing in. The companies are pushing hard for the Emanuel administration to eliminate some of the project’s key features for speeding up bus service.

Along the route’s initial leg, which would stretch from Cortland Avenue to 31st Street, the competing interests are obvious.

Just outside Rush University Medical Center, one of four major hospitals in the Illinois Medical District, a half-dozen patients and staffers huddled in the cold one evening this week at a bus stop. They included Larry Coldiron, a Rush computer consultant who lives near Midway International Airport and gets to ride the CTA’s Orange Line train for most of his commute. But his trip home starts with the Number 9 bus down Ashland — the city’s most heavily used bus route. He said the 2.5-mile journey between the hospital and train usually takes 45 minutes.

“I’ve been doing this for 16 and a half years and it just keeps getting worse,” Coldiron said.

The BRT project would bring big changes. The buses would have a lane to themselves on both sides of a landscaped median. To keep the buses moving through intersections, most opportunities to turn left from Ashland would be eliminated and many traffic signals would favor the buses. Passengers would board from platforms averaging a half mile apart. The CTA is also aiming for pre-paid boarding to eliminate lines in bus doorways. The project’s environmental assessment says the BRT buses would move up to 83 percent faster than today’s buses.

“I’d like to see it,” Coldiron said. Service that fast could attract some of his coworkers who now drive and pay for parking around the hospital, he said.

That’s exactly the idea, said Benet Haller, a top planner at the Chicago Department of Housing and Economic Development. “They would have more money to spend on other things — like food, retail goods and housing.”

Haller said the BRT line would promote development in the medical district, where employment already totals 29,000, and in industrial areas along the route. He said it would also give a shot in the arm to many restaurants and retailers, especially ones that lack their own parking lots. Haller said the economic impact could extend throughout the Chicago region.

“All of our expressways are, pretty much, at capacity,” Haller said. “There’s no real easy possibility to improve any of them. So, if we want to thrive, it’s really going to come to reinvestment back in the central part of Chicago because it’s the one part of the region in which there’s a really robust transit network.”

THE CTA IS GUNNING TO BUILD the initial leg by 2017. Agency officials say they will apply for Federal Transportation Administration grants to cover an estimated $60 million in costs for detailed design and construction. Later phases would extend the BRT to Irving Park Road and 95th Street and cost another $100 million, the agency says.

But there would be other costs, particularly to local businesses whose lifeblood is truck delivery. Those include Kennicott Brothers, an employee-owned flower wholesaler centered at 452 N. Ashland Ave., about a mile north of the medical district.

Dan Andrews, a Kennicott manager, says the company runs 13 vans from that location for deliveries to neighborhood florists, grocery stories and companies that help throw events such as weddings and parties. “Normally our customers will order in the morning,” Andrews said. “We’ll load up the van with orders for that day and then send them out.”

Andrews is worried because the BRT design would leave just one lane on each side of Ashland for cars, trucks and regular buses, slowing down the Kennicott vans. “It would probably be like rush hour all day,” he said.

The CTA acknowledges that the Ashland traffic would move slower. A spokeswoman says a peak-hour car trip that now takes 30 minutes would take 36 minutes with BRT in place.

Another concern for Andrews is the loss of intersections for turning left off Ashland. “With the BRT line, I’d have to take three right turns and then I would have to go through a residential area.”

Andrews has more than deliveries to worry about. Many of Kennicott’s customers pick up their flowers. “If they can’t get to our location, they’re going to choose either another vender or they might choose to be delivered to,” he said, pointing out expenses associated with deliveries.

If Chicago sticks with its BRT plan, Andrews says his company might have to find a location away from Ashland Avenue. “It costs you a lot of money to move your company,” he said.

Economic-development groups in the Kinzie corridor are speaking up for businesses like Kennicott. “These companies need every advantage they can to compete in our city,” said Roger Romanelli, executive director of the Randolph/Fulton Market Association.

“Nealey Foods has about 40 trucks every morning,” Romanelli said, reeling off names of businesses potentially hamstrung by the BRT project. “These companies are critical to our economy.”

Romanelli says slowing the traffic down and banning the turns would also be unfair to big retailers like Costco, which employs more than 100 people in a new facility at Ashland and 14th Street. He points out that diverting traffic to other congested arteries would not much help much.

The Emanuel administration, Romanelli says, ought to scrap the Ashland project and focus on existing buses. Romanelli suggests speeding up service by simply eliminating some stops and using transponders to give buses longer green lights. “BRT is not the only solution for Ashland Avenue,” he said.

A FEDERALLY REQUIRED 30-DAY PERIOD for public comment about the environmental assessment ended Friday. Now Mayor Emanuel’s administration has to decide whether to make adjustments that might please the plan’s business critics but slow the bus service.

Randy Blankenhorn, executive director of the Chicago Metropolitan Agency for Planning, describes the clashing interests. “Planners always want the 100-percent solution,” he said, pointing to the goal of regional economic growth over the long term. “And local businesses are worried about the bottom line today and tomorrow.”

Blankenhorn says the city should help companies find ways to bypass Ashland and maybe even allow a few more left turns across BRT lanes. “But you have to protect the integrity of the transportation investment you’re making,” he said.

On Ashland, that means a bus system fast enough to attract thousands of new riders.

Chip Mitchell is WBEZ’s West Side bureau reporter. Follow him on Twitter @ChipMitchell1 and @WBEZoutloud, and connect with him through Facebook, Google+ and LinkedIn.