Jason Olson, Deseret News
Traffic moves along the Legacy Parkway in Woods Cross during the morning commute.

Transportation planners along the Wasatch Front are burdened by two simple facts of life. Their territory is a confining strip wedged between mountain ranges and the Great Salt Lake. It also happens to be a place of continuing population growth, which shows no sign of abating in coming decades.

These present two contravening forces, putting planners involved in a proposed extension of the Legacy Parkway in Davis County between the proverbial rock and a hard place.

Residents of Farmington City and surrounding areas recently staged a protest over plans to add 24 miles to the highway, along sensitive wetlands and through the town's western neighborhoods known for their bucolic appeal. They argue an extended parkway will be disruptive to both community life and sensitive environmental areas, and they would like the Utah Department of Transportation to rethink pans and seek alternatives.

From UDOT's perch, the issue takes on a different light. The agency is charged with creating and maintaining adequate transportation arteries, and there is a documented need for an expanded infrastructure in that area to serve future commuters.

This is not an either/or proposition. There is no real alternative to additional mileage along the Legacy, unless accepting a state of chronic congestion on I-15 and the existing parkway is on the table. Opponents of the extension argue in favor of additional mass transit options, carpooling and other ways to reduce traffic.

But mass transit systems cannot realistically keep up with the growing number of daily commuters, or the growth in service vehicle traffic needed to support the thriving bedroom communities of Davis and Weber counties. Carpooling can be effective, but only up to a point. If traffic loads increase by 25 percent, 1-in-4 cars would need to become a pool vehicle just to maintain the status quo.

If this discussion elicits a moment of deja vu, it's because we have been down this road before, so to speak. Nearly two decades ago, construction of the existing Legacy Parkway was held up in court as a result of concerns from local residents and environmentalists over the highway's impact on wetlands and adjacent communities. What resulted was a detailed settlement that significantly changed the nature of the project.

In short, the traditional highway that was contemplated became the current "parkway," built with an eye toward mitigating its obtrusiveness. The state agreed to hold the speed limit to 55 mph, to prohibit truck traffic, ban billboards and to use noise-limiting asphalt. It was a hard-fought process of compromise that left neither interest completely satisfied. Residents got a less obnoxious highway; UDOT had to spend more money to build it.

The birth of the original Legacy may offer a template for its proposed extension, one that requires both sides to commit to a fair process of discussion with open minds. The forces that conspire to require new transportation routes are considerable. It is therefore not wise to frame the discussion in terms of whether or not an extension is necessary, but rather exactly where and what kind.

These are the most difficult kinds of public policy decisions, with implications that go beyond any individual's backyard. Everyone along the Wasatch Front has a stake in maintaining adequate transportation options, as well as in preserving the quality of neighborhoods and the environment.

As the discussion moves forward, it's good to know that a process of balance and compromise is a significant part of this highway's recent legacy.