In Denver’s Union Station, the Great Hall, a grand public foyer, is unlike most bench-filled waiting rooms. On a recent visit, clusters of friends shared cocktails after work, mobile office workers tapped at computers from a library table, backpackers lounged on sofas, diners grabbed upscale burgers and one homeless man enjoyed the comfort of a wingback chair.  The 1914-vintage downtown landmark underwent a $54 million renovation completed in 2014 that filled the sprawling, blocklong station with a roster of restaurants and bars by some of Denver’s top chefs, branches of local shops and a stylish 112-room boutique hotel, all while preserving its use as an Amtrak station.  As of April 22, the station took on a new role as the city’s transportation heart when the electric commuter rail line from Denver International Airport, 22.8 miles east, began making the 37-minute trip into the city.  The station is the focal point of a $500 million project to reorder Denver’s transit system, creating a hub for Amtrak, additional light-rail lines throughout the city (three are expected to open this year) and local and national bus services. Currently an estimated 30,000 commuters and visitors use Union Station daily. With the introduction of the new airport train, named the University of Colorado A Line, management expects traffic will climb to 104,000 people daily by year’s end.  “Rail built this town back in the day, and it’s fun to see it’s sustaining it again,” said Nate Currey, spokesman for Denver’s Regional Transportation District, which is overseeing the transportation plan.  Since the airport opened in 1995, officials have been working to link it via rail, and Union Station, down to about two trains a day at its slowest and virtually abandoned, was a natural end point.  “We were dreaming in the ’90s of the possibility of turning Union Station into a hotel, but we realized it needed to be more than a hotel, rather a community hub for people who lived, worked in and visited Denver to come together,” said Walter Isenberg, chief executive of Sage Hospitality, which manages the station’s new hotel, the Crawford, and is a member of the Union Station Alliance, which refurbished the building. “Early on we said the Great Hall needs to become Denver’s living room.”  That central 12,000-square-foot lobby, with impressive Beaux-Arts reproduction chandeliers hung from 65-foot-high ceilings, was already bustling before the beginning of the airport train service. The hall multitasks as the lobby of the hotel, Amtrak’s waiting room and a dining destination. A series of eating spots edge it, including Terminal Bar, serving Colorado-made craft beer from the station’s original ticket windows. Other choices, all locally owned businesses, include Acme Burger & Brat Corporation (acmeburgers.com), Pigtrain Coffee (pigtraincoffee.com) and Milkbox Ice Creamery (milkboxicecream.com).  On either side of the central hall, two long wings house shops and restaurants. The shops include a branch of Denver’s beloved Tattered Cover Book Store (tatteredcover.com) and the gift shop 5 Green Boxes (5greenboxes.com).  Restaurants represent a collection of Denver favorites such as the popular breakfast spot Snooze an AM Eatery, as well as some of the city’s hottest chefs. Run by the chef Alex Seidel, Mercantile Dining & Provision (mercantiledenver.com) combines an all-day market specializing in artisanal products like pickled vegetables and fine cheeses, and a dinner-only farm-to-table restaurant.  In the opposite wing of the building, the chef Jennifer Jasinski runs Stoic & Genuine (stoicandgenuine.com), focusing on seafood and featuring a raw bar.  Upstairs, spread over three levels, lies the Crawford Hotel (thecrawfordhotel.com) with 112 rooms ranging from narrow Pullman rooms, named after the historic train cars, overlooking the tracks, to more elaborate loftlike suites with exposed beams and freestanding bathtubs. The Crawford, which offers tours of the station on most Fridays, also runs the station’s most elegant bar, the Cooper Lounge, located on the mezzanine level and overlooking the station’s Great Hall beneath striking arched windows.  The hotel pays homage to Dana Crawford, Denver’s seminal preservationist who is credited with saving much of the area, known as Lower Downtown, or LoDo, beginning in 1965 with nearby Larimer Square. She has led the fight to protect many of the four- and five-story Western Victorian buildings established shortly after Denver was founded in 1858 and thrived as a shipping center and gateway to the West.  The airport train runs every 15 minutes between about 3 a.m. and 1 a.m. the following day and provides a convenient alternative to renting cars or paying expensive taxi fares. From the spacious plaza in front of the station, riders are surrounded by former warehouses and mercantile buildings now hosting shops, restaurants, breweries and residences.  “One of the fun things about the station is it has a big neon sign that says, ‘Travel by Train,’ ” Ms. Crawford said. “It’s come a full cycle.”  A version of this article appears in print on May 1, 2016, on page TR4 of the New York edition with the headline: Denver’s ‘Living Room’ Expands Its Role, Again. Order Reprints| Today's Paper|Subscribe
Union Station’s new link to Denver’s airport — along with notable restaurants, shops and a hotel — make it the city’s transit heart.