For 50 years, transportation engineers obsessed about building roads that moved as many cars as possible as rapidly as possible. Pedestrians and bicyclists were afterthoughts.

Then, as habits in many cities began to change, engineers rebalanced their thinking. Where conditions and budgets allowed, they lowered speeds and installed bike lanes, crosswalks and sidewalks. They began paying more attention to local sensibilities -- including safety -- and less to the needs of drivers passing through.

But the transition remains slow, painful and sometimes tragic, especially along busy, high-speed thoroughfares in suburban settings. The Hwy. 10 corridor in western Anoka County is one such setting.

In the last four months, four pedestrians have been killed while trying to cross Hwy. 10. The latest was Hannah Craft, 16, of Ramsey, who died on Nov. 26 as she tried to cross near Verndale Avenue.

As along most of that stretch, there are no traffic signals, crosswalks or sidewalks at Verndale. The posted speed limit is 60 miles per hour.

Unfortunately, that segment of Hwy. 10 is of a type that's typical in the Twin Cities and around the country. It's a dangerous hybrid -- neither a controlled-access freeway that separates cars and pedestrians nor a multiuse community street, but something in between, something that resembles a deathtrap.

Traffic moves rapidly along these roads, but with numerous turnoffs to roadside businesses and residential clusters. Without sidewalks or crosswalks, and with few traffic lights (fewer than one per mile), pedestrians and bicyclists are tempted to take terrible chances.

Craft's tragic death prompted the Minnesota Department of Transportation to resume studying a project that had been abandoned nearly six years ago for lack of money. Back then, the cost of upgrading to freeway standards the seven-mile stretch of Hwy. 10 from Main Street in Coon Rapids to Armstrong Boulevard in Ramsey was estimated at $300 million. Included were extensive land purchases and a realignment of the roadway through Ramsey.

The new study will focus more narrowly and modestly on the five-mile segment west of the Rum River. No major land purchases are anticipated. Apparently MnDOT will not consider turning the segment into a slower-paced community street. The volume of commuter traffic -- 40,000 vehicles per day -- is simply too great; a massive bottleneck would result.

The agency will, however, investigate where pedestrian bridges and other grade-separated crossings should be added in order to allow auto traffic to maintain speed while protecting pedestrians, bicyclists and slower-moving cars.

"We want to make changes that allow us to move toward a future freeway," said Wayne Norris, the north area manager for MnDOT's metro division.

A consultant will be hired early next year with the aim of completing the study within a year and a half, Norris said. The cost of improvements is not yet known. That this dreadful segment was nowhere to be found on MnDOT's 20-year construction plan is a sad commentary on the shape of Minnesota's lagging transportation network.

The problem isn't just local. Infrastructure, once a bipartisan priority, has become an ideological issue, and by most estimates, the United States has fallen $2 trillion behind on repairs.

As for safety, the picture is mixed. In a report last week, the National Highway Traffic Safety Administration put road deaths in 2011 at a 62-year low, explaining that driving is getting safer for a host of reasons, among them safer cars, safer roads and better driving habits.

But deaths of other users continue to rise -- up 8.7 percent last year for bicyclists and 3 percent for pedestrians. Carelessness and bad decisions surely play a part in those deaths. But as walking and biking become more popular, badly designed roadways like Hwy. 10 must be made safer for all users.