Rush hour traffic is backed up along Interstate 66 in this view from the Vienna Metro Station on May 19. (Nikki Kahn/The Washington Post)

Mark Sickles, a Democrat, represents the 43rd District in the Virginia House. Mitch Weintraub is chairman of the Fairfax County Chamber of Commerce.

Northern Virginia continues to suffer unbearable traffic congestion. After decades of underinvesting during periods of extraordinary growth and despite key federal earmarks providing major project relief in the 2000s, Virginia has been unable to develop a functioning transportation network.

In 2013, with the unwavering support of the business community, including the Fairfax County Chamber of Commerce, a bipartisan majority in the General Assembly passed a long-term transportation funding measure to help get Northern Virginia moving and to repair the substandard pavement in every corner of our planning district.

Our needs are so great, however, that everyone is justifiably intent on making sure our new revenue is put to its most rational and efficient use.

As Northern Virginia businesses continue to see a reduction in federal spending, a working transportation system is especially important to draw non-federally dependent businesses here and to safeguard our long-term success.

One clogged corridor that must be addressed is Interstate 66 outside the Beltway. The rapid growth of western Fairfax County and Prince William County will mean more congestion. One year ago, Northern Virginia business leaders and many of the region’s elected officials applauded Gov. Terry McAuliffe’s (D) promise to deliver improvements to this section of I-66 , bringing relief to thousands of commuters and businesses stuck in daily gridlock.

The proposal McAuliffe outlined is bold and capital-intensive. Recent estimates suggest that the cost of these improvements ranges from $2 billion to $3 billion. While new transportation revenue has just started to deliver relief and improved pavements, Virginia’s infrastructure needs far outpace resources on a pay-as-you-go basis. So we must continue to identify innovative and creative ways to deliver on the promise of reduced congestion and improved quality of life.

One solution we have used recently to meet Virginia’s transportation funding challenges is public-private partnerships. These allow the Virginia Department of Transportation to direct revenue to other regional priorities. By leveraging private investment, Virginia can deliver big projects more quickly and free up remaining funds without affecting the commonwealth’s borrowing capacity.

Private investment in transportation infrastructure is a popular concept, especially since nobody believes we are headed back to the days of federal munificence as our highways and bridges live on past their design life. Recently, Sen. Mark Warner (D-Va.) introduced the BRIDGE Act, which would establish an infrastructure financing authority and leverage private investments with those from federal, state and local sources. This concept has also been championed by Hillary Clinton, who recently renewed her commitment to the creation of an infrastructure bank that uses a public-private partnership approach to infrastructure funding.

Virginia is considered a leader in these efforts, learning from bad contracts in southeastern Virginia and very good, popular projects here. In Northern Virginia, two such partnerships were used to construct the Interstate 495 and Interstate 95 express lanes. Construction was completed safely in record time. The projects generated more than $5 billion in economic activity, supported 28,000 jobs and issued $765 million in contracts to small and female- and minority-owned businesses. By attracting $1 billion of private equity to deliver the I-66 project, there is every reason to believe we can repeat these successes.

If we can leverage private funds for big projects, we can save resources for corridors that do not lend themselves to a public-private partnership solution.