He also wants to negotiate a new tax agreement with Gov. Andrew M. Cuomo of New York that would tax wages based on where people live, not where they work, similar to the agreement New Jersey has with Pennsylvania, and then using tax proceeds to improve infrastructure.

Jim Johnson, a Democratic candidate, was the first to unveil a transit and infrastructure plan in late April, after spending days experiencing with fellow travelers the disruptions triggered by the derailments. He then convened transportation panels before rolling out his recommendations.

His plan is centered on a “unified vision for a transit system” that would include mandating that organizations such as New Jersey Transit and the Department of Transportation share data and communicate better. Regarding new projects, Mr. Johnson said he would push to complete a long-delayed rail line between Glassboro and Camden as part of a reinvestment in transit infrastructure in the southern part of the state.

To pay for his ideas, he argues, his plan to cut waste, fraud and abuse through an ethics overhaul as well as a tax reform proposal would help generate new financing for New Jersey Transit. Mr. Johnson has also promoted the idea of “predictive maintenance,” making repairs before they become a crisis and costs balloon, similar to a process put in place in Illinois.

John S. Wisniewski, who has focused on transportation issues during his roughly two decades in the Assembly, points to an amendment he introduced twice over the past three years to the state’s Transportation Trust Fund, which finances public transit and highway projects, as a way to pay for improvements.