A section of the four-lane I-5 Bridge fell into the Skagit River in Washington State last week. Witnesses said it disappeared in a "big puff of dust." Fortunately, all motorists were spared - in contrast to the I-35W Mississippi River Bridge collapse in 2007 that killed 13 - although several were injured. This is in addition to the collapse of a highway overpass in Missouri early Saturday, which was caused by a train derailment.

The dated I-5 Bridge collapsed because a truck with a tall load struck an overhead steel girder, weakening it. The truck should not have been on the bridge. For a bridge built in 1955 with a vertical clearance of only 14.6 feet, the risk of oversized trucks accessing the bridge could have been reduced with additional infrastructure investment. Steel overhead gantries on both bridge approaches slightly lower than its maximum clearance, along with a series of height warning signs leading to the bridge, would have stopped overly high trucks from accessing the bridge.

This incident highlights a critical reason for utilizing public-private partnerships (PPPs) in managing the nation's bridges and tunnels. PPPs--standard operating procedure in many other countries--enable a private operating and engineering firm to assume the maintenance responsibility of a major infrastructure facility. Private partners operate under detailed, competitively bid, fixed-term contracts that lay out clear performance standards, with associated penalties and rewards depending on measurable outcomes. PPP contracts can, for example, specify the safety standards to which bridge and tunnel operation is subject, creating the high-powered incentives necessary to ensure the safety of motorist-customers using the bridge.

Management and operation PPPs create huge social benefits. Through the bidding process, PPPs introduce the forces of competition into the critical service of infrastructure facility operation and maintenance. PPPs allow those operational services to be sourced from firms with global bridge operating expertise to oversee U.S. infrastructure operations. Such firms are aware of, and have experience with, the latest infrastructure facility technologies, including those improving safety and efficiency of operation. New technologies including complex sensors poured with concrete, line paint impregnated with reflective glass, high-tech signage, and many others, dramatically improve motorist safety. Moreover, a PPP contract ensures that the private operator adheres to the maintenance schedule laid out in the contract, which insulates infrastructure maintenance from fluctuations in the state's budgetary process.

PPPs also offer the single most important prerequisite for transportation safety: money. Private facility operators have access to global capital markets, both debt and equity. This enables PPP operators to meet obligations of their contracts, which often include expensive renovations to improve the facility's safety and performance. Indeed, as Washington State Transportation Secretary Lynn Peterson said of the I-5 Bridge: "It's an older bridge that needs a lot of work just like a good number of bridges around the state." PPPs can provide resources for renovation in an era of tight transportation budgets. They reduce the fiscal burden on state and local governments associated with bridge and tunnel maintenance, allowing them to allocate scarce resources elsewhere.

The socially beneficial incentives created by PPPs are made even stronger due to reputation effects. A private facility operator's professional reputation is its most valuable asset. If bridges operated by ABC Company have a habit of failing, ABC will never receive another contract, can be barred from further bids, and will soon be bankrupt. Indeed, one bridge collapse is likely to be sufficient to drive it out of business.

Although some analysts believe the bridge must be tolled to use a management PPP, alternative arrangements can engage private expertise without road pricing. Under an availability payment PPP, the private manager is paid based on counts of the number of cars, trucks, vans and buses. In other words, they are paid based on how many customers use the bridge, just like any service. The PPP contract can specify other aspects of service quality, such as the speed of removing debris from the road and pavement smoothness.

The preferred way to fund a management PPP, however, is by charging motorists directly for bridge use.

Since the bridge provides the service of transporting the driver's vehicle, direct tolling restores the user-pays principle that funds every good and service from apples to window washing. Moreover, surveys indicate that motorists are more willing to pay a toll when they know it is accompanied by critical infrastructure renovations.

User payment is today technologically straightforward. A reader can be placed on an overhead gantry that "talks" to an onboard transponder, such as EZPass, and the driver's account is debited.

Alternatively, the driver's smart phone can sense passage over the bridge and charge accordingly for its use. Those charges create the stream of revenue necessary to attract management PPP bids. The bridge is then effectively run like a utility.

Public-private partnerships have the potential to revolutionize bridge, tunnel, and road operation in the United States. Yet only thirty-two states currently have laws on the books that enable their use. It is time for the United States to catch up to the rest of the world, and to enjoy those benefits. There have been almost 600 bridge failures of one form or another in the United States since 1989. In the world's wealthiest nation, there is no reason to tolerate manifestly hazardous bridges. We should not wait for a fatal bridge collapse to adopt a better policy approach.