Conceived in its simplest form, a light-rail system needs to move people from Point A to Point B.

And in our county, Point “B” stands for Boeing.

The advantages of routing commuter service directly to Boeing would include less highway congestion, reduced parking pressure around Paine Field and greater convenience for workers trying to reach their aerospace jobs.

If these are the sole criteria for expanding light rail northward, the alternative that was included in a Sound Transit presentation last week is a slam-dunk — the line should diverge from I-5 to deliver workers to the state’s largest manufacturing center.

We should recognize, however, this proposal places an overwhelming priority on getting people from King County and south Snohomish County to their jobs at Boeing and adjacent businesses.

A transit system needs to do more than just this. The broader goals of light rail should be to support regional plans for managed growth and to knit together the civic and economic futures of neighboring communities.

The Puget Sound Regional Council (realistically or not) anticipates a drastic increase in Everett’s overall population and downtown density over the next 11 years. How will this be remotely possible?

Foremost, the city needs to be more than a place that’s, you know, “up there north of Boeing.” It needs to be a desirable, accessible spot for people who want to travel north or south for housing, employment, shopping and recreation.

There is a practical reason for mapping the transit route to Boeing: Planners can increase ridership estimates and justify more development money — which is no small thing.

“We can’t go after funding for aspects of a transportation system if we don’t have the planning work ahead of it.” said Everett City Councilman Paul Roberts, who serves on the Sound Transit Board. “This is really opening the door to pursue those dollars.”

But as the massive project drags on and costs invariably swell, a temptation could arise to lower the bar and redefine the goal.

For Boeing, the challenge will only grow worse, as maxed-out parking spurs yet another (real or perceived) incentive to uproot.

“If they can’t add employees because they don’t have places for those employees to park, they’re going to take those jobs somewhere else,” said airport director Dave Waggoner.

The Snohomish County Council and other local leaders need to make sure Sound Transit hears a clear message: The benefits of light rail must stretch beyond Boeing.