Yesterday, City Hall announced it would devote an additional $400 million to Vision Zero street safety initiatives over six years. This morning Mayor de Blasio released more details about how that funding will be spent.

The bulk of the funds — $317 million over six years — will go toward capital projects that involve full street reconstructions. Those investments are durable, but they’re overseen by the Department of Design and Construction, which tends to complete projects years behind schedule. So it may be some time before the impact of this spending is felt.

The stakes for capital projects are higher too. Once the city rebuilds a street, that’s it, there’s no process of trial-and-error to test out different configurations. The city’s capital dollars have to go toward designs that will significantly reduce fatalities and injuries. For a project like the reconstruction of Fourth Avenue in Brooklyn, which is slated to begin this year, that means committing to protected bike lanes, not the current design where people on bikes dodge between double-parked cars and traffic.

The city gets more bang for the buck from the redesigns DOT builds quickly with low-cost materials. In budget negotiations last year, City Council leaders pressed the mayor to increase DOT’s budget for these “operational” projects by roughly $50 million annually, and de Blasio declined.

The spending increase de Blasio announced today didn’t meet that demand, but it will give DOT more resources to make safer crossings and bike lanes.

About $70 million over five years will go to replacing and refurbishing street markings. This funding will prevent crosswalk and bike lane markings from fading to oblivion, with the replacement cycle accelerating from every six years to every four and a half years.

The city will hire 100 additional full-time school crossing guards and 200 part-time guards (at a cost of $25.6 million over four years and $7.2 million annually after that).

A smaller amount — less than $700,000 annually — will fund “targeted safety enhancements and upgrades” at 20 intersections in the bike network per year. We have a request in with DOT about what these intersection changes will entail.

DOT will also receive more funding to implement treatments for safer left turns and “enhanced pedestrian crossings” that have no signal or stop sign but will receive high-visibility markings, and NYPD will acquire 120 handheld speed detection guns, increasing the department’s supply 50 percent.

The increased investment in Vision Zero comes after declines in traffic deaths during de Blasio’s first two years in office flattened out in 2016.

“We have said we must always do more,” de Blasio said today. “Our proposed budget will allow us to keep kids safe around our schools and expand DOT’s most effective efforts to make our streets even safer.