The COVID-19 pandemic is threatening to cast a long shadow over public transit and traffic in the South Bay, as Valley Transportation Authority leaders consider deep cuts to bus and light rail service that could outlast the virus’ grip on our daily lives.

VTA leaders will consider in the coming months three increasingly severe options that would slash service starting early next year by 10 to 30 percent compared to pre-pandemic levels, saving the ailing agency between $24 million and $70 million per year.

In its best-case scenario, VTA would provide less frequent bus and train trips outside of peak commute hours, and light rail service would end an hour earlier each night than it does now.

Under the most severe cuts, VTA would slash the frequency of bus and light rail service at all hours and across its entire network to levels not seen in 40 years. All service would shut down at 10 p.m., and two bus routes would be eliminated entirely.

Transit advocates say the result would be devastating. People who rely on VTA would face longer and less reliable trips, while those with any choice in the matter would be much more likely to drive rather than try to navigate the spotty service — putting more cars onto traffic-choked roads and pumping more greenhouse gases into the atmosphere of our warming planet. VTA estimates riders would take between 3.5 million and 9 million fewer trips per year under the cuts.

“This is something that is really going to cause a lot of inequity, and cause a lot of people to buy cars they can’t afford,” said Monica Mallon, an activist with the group Voices for Public Transportation.

Mallon pointed to VTA records showing that if the agency enacts the proposed 30-percent cut, it would provide less frequent bus service than it offered in 1980 — when 600,000 fewer people lived in Santa Clara County.

After other reductions to VTA service over the past two decades, Mallon said, “We were already in a death spiral, but this would be so much more extreme.”

The impacts would even extend to the Bay Area’s housing crisis: Developments that were eligible for grants or quicker environmental reviews because of their proximity to VTA lines could lose that special status if nearby buses and trains don’t run frequently enough.

And the $2.3 billion South Bay BART extension VTA officials proudly opened this summer could see fewer riders if passengers face a long wait every time they transfer between the train and bus.

“Quality connections and coordinated connections are the foundation of any good transit network,” VTA Service Planning Manager Jay Tyree told the authority’s board at a meeting last week. “When you start breaking those down and folks have longer wait times to connect, then they just give up on transit.”

Agency leaders say they have tried to preserve ridership as much as possible, but face “tough decisions” as public transportation tries to position itself for a post-coronavirus world. VTA has not implemented any layoffs or furloughs to reduce its expenses.

“We are sincerely disappointed that we even have to have these conversations with our riders and the public,” spokesman Ken Blackstone said.

Like other public transit agencies, VTA has since March faced a financial double-whammy. The economic downturn the pandemic triggered has reduced sale tax revenue, by far its biggest source of funding. And the virus has decimated ridership, from about 115,000 daily passengers in February to around 30,000 since April. Many of those who are still riding are essential workers, or residents like Mallon who don’t drive and depend on public transit to get around.

VTA is not alone in considering steep cuts — AC Transit officials could also slash East Bay bus service by as much as 30 percent next year, with plans that call for eliminating dozens of routes and reducing the frequency on many others.

VTA has been providing reduced service for months amid shelter in place orders; since August, it’s been running roughly 74 percent of its pre-pandemic service levels.

But that reduction can’t last. With strict social distancing-driven capacity limits, VTA officials say bus drivers must often skip passengers during busy trips, a problem that seems likely to worsen as more people return to work.

Ultimately, the severity of cuts will depend on a range of hard-to-forecast factors, such as when social distancing requirements might be eased, when schools resume in-person classes, whether state or federal authorities approve another round of emergency funding for public transportation agencies and how quickly the economy bounces back.

VTA officials are set to decide how severe their cuts will be at a meeting in December. The new service would go into effect in February.