Thousands of commuters will board the CTA Red Line along the Dan Ryan branch Monday for the first time in five months after a massive rebuild that will also deliver something its riders haven't experienced in decades: zero slow zones.



Trains along the south leg of the Red Line will operate at regular, posted speeds of up to 55 mph along the whole 10-mile stretch for the first time since shortly after its 1969 debut — without the bumpy, jerky ride that even longtime riders could not ignore.



"The train glides," said Yvonne Marshall, 19, a student at Kennedy-King College, who rode the train Sunday, the day it went back into service. "You don't need to hold on (to the grab bars) like you used to do."



That's 14,255 linear track feet of smooth running, barring any problems. Almost half of the branch was mired in slow zones before work began to rip out the old tracks and replace them with a rail bed that can accommodate up to 70 mph trains, if the CTA ever decides to operate such service.



After 154 days of construction to modernize the entire track and signal systems from south of Roosevelt Road to 95th Street as well as upgrade eight of the nine stations, service was restored at 4 a.m. Sunday on the Red Line south branch.



Alternative service that included free shuttle buses and cost the CTA about $13 million to provide ceased Sunday, and some riders were sad to see it go, CTA president Forrest Claypool acknowledged.



"Riders regularly asked that we keep the bus shuttles because they were faster than the old Red Line service,'' Claypool said Sunday at the 95th Street terminal. "But I have good news for those customers. If you think the shuttles were fast, wait till you see the new Red Line."



Starting Monday during the rush periods on the CTA's busiest rail route, Red Line trains will once again operate six minutes apart between 95th Street and Howard Street on the Far North Side, the CTA said. Off-peak, service is scheduled every 71/2 to 10 minutes, and on 15-minute intervals during the overnight hours.



CTA officials said they are eager to lure back the 10 percent of the roughly 80,000 weekday Red Line riders who abandoned the transit agency in favor of taking Metra, driving or making fewer trips during the five months that the south branch was shut down for the track project, from May 19 through Oct. 19.



"The first few weekday commutes may see a slight dip in ridership, but we expect the numbers to resume fairly quickly to normal or near-normal levels as riders become re-acquainted with their old routines," CTA spokesman Brian Steele said.



The $425 million Dan Ryan branch project was completed on time and on budget, CTA officials said. It was the first total track replacement since the south branch opened, and by doing the work in five months instead of weekend-only closures spread out over four years, the transit agency saved $75 million that it used in station improvements.



About 65,000 railroad ties and 195,000 tons of ballast were replaced along the corridor.



Worn jointed sections of rail that produced bumps each time wheels rolled across the joints were replaced by continuous, welded rail, which provides a softer and more comfortable ride, said Chris Bushell, the CTA's chief infrastructure officer, who stopped shaving on May 19 and vowed to keep his new beard going until the project's completion.



"I'm clean-shaven, but no commitment for how long,'' Bushell told your Getting Around reporter via email Sunday.



More stressful than unkempt facial hair, the contractor on the project, Kiewit Infrastructure Corp., faced penalties of $675,000 a day if it failed to complete work in time for Sunday's planned resumption of service.



Helping improve the ride are 170 new 5000 Series rail cars, representing 44 percent of the 384 cars assigned to the Red Line, the CTA said. The 214 2600 Series cars on the Red Line will be replaced by 5000 Series cars sometime next year, officials said. The 2600 Series was built between 1981 and 1987.



Another major highlight of the south branch project was the installation of elevators at the Garfield, 63rd and 87th street stations, making all stops on the Red Line south branch fully accessible.



"It's a great day for Chicago,'' veteran CTA rail instructor John Zupko said. "The CTA has put the 'rapid' back into rapid transit.''



Many riders who rode the south branch on opening day Sunday agreed, although some said they will miss the free shuttle bus service between closed Red Line stations and the Green Line, as well as the free boardings offered at the Garfield station on the Green Line.



"The shutdown was a big inconvenience to suffer through and I am very happy to have the Red Line back,'' Pat Samuels, a lifelong South Side resident who relies on the CTA and Pace, said at the 95th Street terminal Sunday.



She said the shuttle service worked well for her, but it also was disruptive to the community.



"This neighborhood can now settle down again. It was pretty hectic with all that excess traffic caused by the shuttle buses coming in and out and the rerouting of the regular buses," Samuels said.



Anthony Taylor, 34, who was boarding a northbound Red Line train at the 87th Street station on his way to work Sunday morning, said the temporary shuttle bus service worked surprisingly well. Taking his first Red Line ride in five months, Taylor said he was somewhat skeptical about promises of new and improved service.



CTA officials said commuters will save up to 10 minutes each way between 95th Street and the Monroe subway station.



"I saved a lot of money using the free service, and it was just as fast as the (old) Red Line," Taylor said. "Ten minutes don't mean a lot to me."



The free rides ended Sunday as Red Line trains that were rerouted to the Green Line tracks from May 19 until Sunday returned to the nine Dan Ryan branch stations between Cermak-Chinatown and 95th Street. The 95th Street train and bus terminal will be overhauled starting next year at a projected cost of $240 million.



The CTA has been testing what is essentially a new railroad over the last several weeks in the run-up to this week. A minor glitch occurred Sunday morning when a signal failure halted trains for about 20 minutes between 43rd and 47th streets, Claypool said.



Some riders grumbled about the service delay on the brand-new tracks.



"The train ran smooth, except when it stopped a couple of times near 47th Street," Nyesha Brooks, 21, said after exiting the train at the 95th Street terminal. "I wasn't expecting that at all. It seemed like it too forever between Sox-35th and 47th. But I'm happy the Red Line is back because it's easier.''



Beginning Monday, regular CTA buses that were rerouted during the Red Line project will return to their normal routings, said Steele, the CTA spokesman. For commuters making bus connections at the 95th Street bus terminal, new signage will point out changes in bus bay assignments.



There is another change. In the mornings on the Lake Street portion of the Green Line, two trips will turn back after the Roosevelt elevated station, Steele said, adding the short turns respond to customer requests for more frequent service on the Lake Street "L.''



Contact Getting Around at jhilkevitch@tribune.com or c/o the Chicago Tribune, 435 N. Michigan Ave., Chicago, IL 60611; on Twitter @jhilkevitch; and at facebook.com/jhilkevitch. Read recent columns at chicagotribune.com/gettingaround.