PHOENIX -- Arizona transportation officials will be reviewing inspection records of all 4,720 bridges on the state roadway system in the wake of the Minneapolis disaster -- including three of similar design to that structure.

But there is no guarantee they will physically inspect any of them.

The move comes on orders from Gov. Janet Napolitano who said the state Department of Transportation needs to make "an extra effort'' to ensure that all structures are safe.

Napolitano specifically ordered ADOT to concentrate on high-traffic spans in the state's four major urban areas. And she wants a report back by Sept. 7.

Gubernatorial press aide Jeanine L'Ecuyer said ADOT officials also have promised to make it a priority to review the three steel spans that are built the same way as the eight-lane structure on Interstate 35W across the Mississippi.

ADOT officials have identified these as a bridge over the Gila River on U.S. 191, a span over the Little Colorado River on U.S. 89 near Cameron, and another bridge on U.S. 89 between Chino Valley and Paulden over Hells Canyon.

But ADOT publicist Diane D'Angelo said nothing in the governor's order means engineers from her agency will actually physically inspect those three spans -- or even any of the other 4,717 in the state highway system.

Instead, she said the engineers will review the records of prior inspections, done at least once every two years. Only if there is reason to question the safety would teams go out and look at a structure.

State engineers also will help county officials review the records of two bridges also with steel trust construction: one i Mohave County over Sand Hollow Wash and an Apache County bridge over Querino Canyon.

D'Angelo also acknowledged that there are 42 bridges in the state highway system classified by the U.S. Department of Transportation as "structurally deficient.'' But she said that doesn't make them unsafe. "That is engineer talk for 'needs some work,' '' she said. "

'Structurally deficient' could be, oh gee, the pavement's looking kind of funky there, we need to replace that.''

She said Arizona, blessed with relatively new infrastructure and good weather, has among the best bridges in the country. And the governor's office said the American Society of Civil Engineers has given Arizona an A-minus for highway bridge safety.

"While there is comfort in knowing we have an excellent assessment right now, I want to make the extra effort to ensure that our freeway bridges are safe,'' Napolitano said in a prepared statement.

And D'Angelo said that "there are no structures in Arizona right now that are in danger of anything near the tragedy that happened in Minneapolis.'' L'Ecuyer said the decision on which bridges -- if any -- to inspect will come after the engineers review the records of recent inspections. "It makes sense to me that if it was done last week we're not going to go out and do the same microscopic inspection again,'' she said. "We're going to be able to say, 'OK, we know we were just there. We know we were just at this one. We know we haven't been at this one within the last 18 months, let's go look at it again.' ''

D'Angelo said ADOT spent $20 million last year on "bridge preservation'' efforts, including both inspection and routine maintenance. That figure does not include construction of new spans as a result of highway construction.

D'Angelo said the bridge over the Gila River already is targeted for replacement as part of a larger project to realign the two-lane road. The U.S. Department of Transportation, in a 2005 report, said Arizona has 162 bridges overall that are structurally deficient. Those beyond the 42 in the ADOT system are under the control of other levels of government. That USDOT report also says there are 558 bridges in the state which are "functionally obsolete.''

D'Angelo said she did not know how many of those are in the ADOT system. But she said these are bridges where engineers determine that they could be updated, like adding another lane, rather than questions of maintenance or safety.