Late afternoon and the great haunches of the Allegheny Mountains loomed beside the train's westward winding path.

As Amtrak Train 43 chugged past Johnstown, lengthening shadows cast a melancholy pall over the town's redbrick buildings, remnants of industrialization. Then the train plunged back into forest, where glimpses of the Conemaugh River peeked through the trees.

Final destination, Pittsburgh, was still almost two hours away.

It's nearly 7½ hours on 350 miles of rail from Philadelphia to Pennsylvania's big city in the west. It's slower than an hour-and-15-minute flight or five-hour drive, and, at $47, comparable to the cost of tolls and gas on the Pennsylvania Turnpike. Amtrak's Pennsylvanian, which connects Pittsburgh with New York City for about 230,000 passengers a year, also leaves little room for flexibility.

One train a day leaves 30th Street Station for Pittsburgh, at 12:42 p.m. There's only one return trip, at 7:30 a.m.

Not enough, say Pittsburghers.

"We need more service," said Lucinda Beattie, vice president of transportation for the Pittsburgh Downtown Partnership.

Advocates such as Beattie, who describe the train as Western Pennsylvania's gateway to the East Coast, say better train service would mean fewer cars on the turnpike, economic development for towns on the route, and more mobility for Pittsburgh residents. A 2015 PennDot report on rail service said improvements to the existing line would also likely draw riders from east of Harrisburg.

"There's a real opportunity here for Pittsburgh to be seen as a site that folks from the East Coast have easy access to," said Alex Pazuchanics, policy coordinator for Pittsburgh's mayor.

In August there were hearings about improving the 250-mile Keystone West line, the tracks between Harrisburg and Pittsburgh, and PennDot has asked Amtrak to estimate the cost of adding one more round-trip a day.

Geography and track rights are the obstacles to better rail service in Pennsylvania. As far back as the 19th century, industrialists were frustrated by the current rail route. The trip's most famous stretch is Horseshoe Curve, a scenic bend around a picturesque valley near Lake Altoona, but it also illustrates the problem posed by the Allegheny Mountains. In the mid-19th century, the Pennsylvania Railroad used a route that ribboned between the mountains, rather than tunneling through them. Amtrak trains typically travel close to 80 mph, but many of those sharp turns require the train to slow. The average speed on the line is 45 mph.

The 250 miles of tracks between Harrisburg and Pittsburgh belong to the freight carrier Norfolk Southern. About 60 freight trains a day use the route, said Dave Pidgeon, a spokesman for the rail company. Passenger trains stop to make way for freight behemoths up to 130 cars long carrying products from the Great Lakes region to the East Coast, he said. And Norfolk Southern charges Amtrak to use the tracks. Amtrak didn't disclose the fees but said the cost varied based on miles traveled and incentive payments for on-time performance. Each additional train would cost more in usage fees, officials said. As for track improvements that would allow faster travel, Norfolk Southern officials said it wasn't a priority for them.

"We right now have a robust rail network that is serving our customers," Pidgeon said.

Federal law requires Pennsylvania to support 100 percent of the operating costs for passenger rail in the state, about $14 million annually now.

The state expects an additional round-trip to cost $10 million to start, and an additional $6 million each year in operating costs. Track improvements to allow faster trains would run between $1.5 billion and $13 billion, according to a 2015 PennDot report. The most ambitious option, straightening the route and adding an additional track in places, would shorten the trip by just a half-hour in each direction. Major construction to make the trip shorter isn't likely any time soon, said Leslie S. Richards, Pennsylvania's transportation secretary.

"The only way we would make a major investment is if we could reduce that time," she said.

The state calculated a price estimate of building a completely new track to parallel the Pennsylvania Turnpike's more direct route to allow true high-speed travel and dismissed the option. It would cost about $88 billion in construction and land acquisition. Ironically, the turnpike was built in part on the right of way of a never-completed new rail route across the state designed to circumvent the very problems that plague the state's rail travel today.

The state's efforts to improve service focus on increasing frequency, rather than speed, Richards said. Adding one round-trip could have a big impact. The PennDot report projected 144,000 additional trips along the Pennsylvanian route with an added train in each direction.

Sitting in the train's cafe car, watching Lancaster's farmland give way to mountains, it's hard to argue there's a more comfortable way to travel.

Riders vary from people in traditional Mennonite garb to a heavily pierced woman hunched over a laptop who identified herself as Meliora Angst. Nearby, a group of retirees played cards in one of the booths. One of them, William Ryckman, a retired doctor, said they were heading home after a visit to New York City. Angst was also homeward bound from a visit with a boyfriend in Lancaster. They are representative of many of the train's users, people visiting friends or family or traveling to appointments at top East Coast hospitals.

Amtrak believes the comfort of train travel is a major selling point compared with hectic airports or tiring drives.

"The train affords you many different amenities even if you were flying or driving," said Joe McHugh, Amtrak's senior vice president for government affairs and corporate communications.

Amtrak is a long way from adding another train, he said. After giving PennDot the cost estimate, further studies will have to be conducted, including looks at traffic flow, ridership, and revenue, and negotiations resolved with Norfolk Southern. In other parts of the country, that process has taken as few as two years and as many as 10, McHugh said.

Rail would seem to be a natural fit for a former industrial powerhouse nicknamed the Iron City, but it's Pittsburgh's new identity as a tech hub that will likely drive interest in better train service. Google, Uber, and the German engineering conglomerate Robert Bosch LLC all have offices in Pittsburgh, and Beattie thinks the state isn't asking for enough. The route needs two more round-trips, not just one.

"If you take the train to Harrisburg, it's a three-day trip," Beattie said. "A service that gets you back in one day would be great."