Improvements to infrastructure have slowed in the US over the past few decades as costs have risen and environmental review timelines have lengthened. These changes have real-world implications. Although the US had the longest network of metro rail lines in the world as late as the 1970s, for example, China and the European Union now have far longer networks.

Researchers have identified two major factors contributing to slowed investments in transportation. An increased use of community engagement in planning processes can lead to delays—and even cancellations—in transportation projects. And the bureaucratic decisionmaking structures of the governments overseeing these projects divide elements of policymaking among many different elected and appointed officials. Ultimately, a slowdown in new investment means less effective transportation systems, which is problematic because people need affordable access to employment, education, health care, and other needs.

In new research I recently published in Urban Affairs Review, I pinpoint a third challenge for infrastructure investment: the powerful role local government officials play in influencing project design. I show that, even when they’re not formally involved in a project, local leaders like mayors and city councilors leverage their unofficial power to change project design in ways they prefer. As a result, projects sometimes become more expensive, or their completion is delayed.

Input from local elected officials is not necessarily a bad thing. Sometimes projects evolve for the better thanks to their input, and they may play an important role in reflecting the views of community members whose perspectives are unaccounted for in higher-level governments’ decisionmaking. But massive cost increases and project delays pose obstacles to the vision of achieving more abundant access to transportation in a timely way.

Local leaders’ influence is arguably more challenging to address than community engagement or governmental structures because it’s the result of informal relationships, not laws or regulations. Still, policymakers hoping to speed infrastructure investment and help more people access transportation can better account for local elected officials’ unofficial power. Setting maximum timelines for project deliberation and developing mechanisms to quickly measure potential changes to projects to ensure their benefits exceed their costs are two steps policymakers can take.

Major transportation projects often span multiple jurisdictions, which have their own priorities

Transportation projects in the US typically cross through multiple localities. For example, the Metro Green Line project being built between Minneapolis and its suburbs will run through five cities once completed.

Minneapolis’s Metro Green Line isn’t atypical. Using an international database of urban transit, I reviewed the routes of the dozens of transit projects currently under construction in the US. I found that 66 percent will extend across multiple municipalities, and about 25 percent will extend across four or more. This reflects the reality that economies are metropolitan in scale, and transportation investments respond to the need to move people from home to work at the same scale.

The fact that projects span multiple jurisdictions has a political implication. Elected officials all along a project’s route may want to influence outcomes—even if they technically have no official role in making policy choices. Collectively, the localities along the Green Line have 38 elected city councilors and mayors—all of whom might have something to say about the project’s design, which could complicate its construction.

Local leaders have substantial power over projects, even when they have no official role

In my research, I explored multijurisdictional planning conditions for new transit lines in three metropolitan areas. I reviewed the official governance structures of the transit projects, then interviewed dozens of elected officials and transit planners potentially affected by the lines.

From a legal perspective, leaders of higher-level governments (e.g., counties and states) control project design decisions. Initial plans for Minneapolis’s Metro Green Line were approved by the Hennepin County Regional Railroad Authority, which is made up of the county’s board members. Now that the line is being built, the Metropolitan Council, a regional agency whose board is appointed by the governor, oversees the project. My review of documents outlining the project’s governance structure showed that, officially, lines of decisionmaking for the project were relatively straightforward, not split up between many governmental bureaucracies. Similar conditions were present across the other projects I examined.

But my interviews suggested that, in practice, transportation projects lacked clearly defined governance. Officials managing decisionmaking for higher-level governments—who are technically in control—often deferred to the points of view of locally elected officials. This shows that though their role is informal, local officials play an essential part in shaping project plans.

At the same time, higher-level governments don’t always take ownership over the projects they’re leading, promoting local points of view instead. One staffer of the Metropolitan Council said, “[We] aren’t trying to dictate [projects’] path or the purpose,… [we’re] just giving advice on how this will fit into the regional context.” This is despite the fact that the Metropolitan Council operates the transit system and, in many cases, absorbs the costs of project construction.

In some circumstances, projects became more expensive as higher-level governments considered local officials’ perspectives. In the Green Line’s case, one mayor successfully argued for a rerouting that added $200 million to the project budget. Other projects I examined were subject to years of delay as mayors contested project plans.

States should mandate quicker timelines to improve transportation infrastructure

Local leaders, such as mayors and city councilors, are likely to retain considerable informal influence over higher-level governments’ decisionmaking on transportation projects, even if they have no official role on a project. Though their input can improve projects, it can also cause detrimental setbacks.

Putting boundaries on the planning process could encourage more infrastructure development. One approach state governments could consider is constraining project decisionmaking to a tight timeline. Rather than allowing the decisionmaking process to extend indefinitely, this could mean requiring that final choices about major project issues—such as route alignments—be made within a short period by whatever agency is in charge of planning. If they cannot make a decision, the state department of transportation could step in.

Another option to consider is requiring proponents of potential project changes—whether they have official power over the project or not—to show that these alterations’ benefits will outweigh their costs. To make this approach feasible, the public would need free, easy access to tools that measure outcomes such as access to jobs and opportunities for housing development under various scenarios.

By better accounting for local leaders’ influence on transportation projects, policymakers can help more people access transportation and other infrastructure that facilitate their employment, education, and participation in other opportunities.