FALMOUTH, Maine — Just five miles apart, bounded by the same river and home to some of the same stores, U.S. Route 1 and state Route 100 seem to follow parallel paths through Falmouth.

The Route 1 business corridor is a subject of scrutiny as the Falmouth Shopping Center is in the process of being sold and the Town Council prepares to unveil a new plan for developing the corridor.

So are changes along Route 1 signs of things to come for its sibling to the west?

The similarities between the two roads are striking. Both run roughly north-south, crossing the Presumpscot River and connecting Cumberland, Falmouth and Portland. A shopping complex along Route 100 is anchored by a Hannaford supermarket; the Route 1 district features a Shaw’s supermarket.

Looking for a dry cleaner? You’ll find Pratt-Abbott Cleaners on each highway. Need your hair trimmed? Supercuts salons are just off each route.

Both routes offer easy access to the Maine Turnpike and METRO bus service. Even the color schemes are similar: shopping complexes in both areas are painted pale yellow.

But the two business districts differ in other ways.

The town has wrestled for 10 years with how to redevelop the Route 1 district into a more pedestrian-friendly “village” of shops and multi-use buildings.

One outcome of that effort is a zoning amendment introduced last week to limit the footprint of new or expanded commercial buildings in the Route 1 district to 30,000 square feet. Grocery stores could occupy a footprint of 60,000 square feet.

But a village of small-footprint development doesn’t lie in the future of the Route 100 area, said Town Councilor Tony Payne, a member of the council’s Community Development Committee.

“You’re never going to have the residential density of a village in West Falmouth,” he said.

Despite commercial growth in the stretch between Leighton Road and the river, much of Route 100 maintains a rural feel, with small, sparse buildings.

“The town has taken conscious measures to preserve the rural character of the area,” Payne said. “We’ve heard over and over again from residents that they don’t want that character to be lost.”

The town is working to preserve the area’s character through a mix of zoning regulations, but some people are unhappy with the results.

One such person is Peter Wormell, owner of Harmon’s Lunch, a diner at 144 Route 100. Harmon’s opened in 1960 — just two years before the Falmouth Shopping Center.

Today, storefronts at the Route 1 shopping center sit empty. Across town, business has been slumping at Harmon’s, too.

The diner is known by residents for its legendary hamburgers, but sold 11,000 fewer of them in 2011 than it did in 2007, Wormell said. Most of that decline occurred last year.

In response, Wormell decided to add carryout ice cream to his menu. But when he recently tried to obtain town approval for a carryout window, his request was denied.

Carryout and drive-through windows are not permitted by rules of the zoning district where Harmon’s is situated. But just a mile south on Route 100, next to Hannaford, customers order coffee at a Dunkin’ Donuts drive-through.

The coffee shop is in a planned development district that gives more flexibility to developers. Fast-food restaurants in the Route 1 business district also are allowed to operate windows.

“The difference in zoning doesn’t make any sense to me,” Wormell said.

Outside of Harmon’s, customer Adriaan Bishop was also puzzled — by the number of cars and trucks passing the diner.

“Traffic on this road has definitely picked up because of all the new business here,” he said. The town “has to do something, but I don’t know what can be done.

“Ten years ago, you wouldn’t have seen so many cars. There really wasn’t much reason to come out here, except for Harmon’s. Now there’s a steady stream of traffic,” said Bishop, who grew up in the nearby Portland neighborhood of North Deering.

Traffic management is an area where the town has learned from its experience with Route 1, according to Payne.

“We’ve learned that we have to be especially mindful of the impact of what we do on traffic,” he said. “That’s one of the most important pieces.”

Causes of traffic growth in the corridor may not even turn out to be local, the councilor suggested.

“It’s not clear what’s happening north of us, or what impact it may have,” said Payne, referring to commercial development in Cumberland and Yarmouth. And with gas stations and convenience stores just yards away from Maine Turnpike Exit 53, Route 100 is an attractive stop for highway travelers.

Regardless of the traffic source, Payne said, planning for the future of both routes requires discussion that involves the entire town.

“We need to make a conscious decision,” he said. “Does Falmouth want to grow, and where does it want to grow?”