Mayor Ed Lee is rolling out another taxpayer giveaway, this time to Silicon Valley technology companies. Lee wants to permanently share an unlimited number of our public bus stops with an unlimited number of private shuttles that ferry employees for free from San Francisco to their jobs.

But on Tuesday, the San Francisco Board of Supervisors will hear an appeal of this plan to replace the 18-month pilot program with a permanent one. The pilot program ends Jan. 31.

The appeal is based on:

• the absence of an environmental impact report and the required mitigations that result from such reports.

• the illegality of the program.

State law, with good reason, explicitly forbids any vehicle except public buses and cabs (and sometimes school buses), from operating at our public bus stops. The law outlaws big, fat private buses from blocking access for senior and disabled riders to public buses, outlaws slowing down Muni buses and trams, and preserves the ability of public transit — which is accessible to all — to expand as we take more and more steps to reduce congestion and greenhouse gas emissions.

Assemblyman Travis Allen, R-Huntington Beach, recently tried to amend that state law for the tech firms. An army of organizations, including San Francisco Democratic clubs, disability advocates, the Muni operators’ union TWU Local 250A, United Educators of San Francisco, Unite Here Local 2, and, at the state level, SEIU and AFSCME, sent Allen a message: Oh no you don’t. He pulled the bill. He introduced a new bill to the same end this month.

The 18-month pilot program analysis documents shuttle interference with travel and bicycle lanes 35 percent of the time, and a gallery of photos documents interference with Muni.

Just as alarming, evidence indicates that the availability of the shuttles — in November 2015 there were 479, equivalent to more than half of the Muni rubber-tire fleet — drives up housing prices, fueling the demographic turmoil hitting San Francisco and the Bay Area.

Now imagine an unlimited increase in private shuttles and public bus stops incorporated into the shuttle program.

Apple could employ as many as 27,900 additional employees at its two new campuses in Silicon Valley. Other Silicon Valley companies are also expanding. These companies offer as a perk to their employees living in San Francisco free transportation to and from their jobs. Meanwhile, the shuttle companies pay a revenue-neutral fee of $3.67 per stop per day to the San Francisco Municipal Transportation Agency. Tech companies get tax write-offs for providing free transportation to employees.

And yet, no environmental impact report has been done on this private transportation system with the potential for unlimited growth, unlimited interference with Muni, unlimited demographic disruption and unknown air quality impacts. (An air quality analysis done as part of an ending 18-month pilot program failed to evaluate projected air quality if the program expands, as expected.)

The tech companies could build workforce housing so as not to disrupt the rest of the Bay Area. But without an environmental impact report, they don’t have to do anything.

We purchase the tech companies’ products gleefully. Now let’s demand that they be better corporate citizens. Please write to the Board of Supervisors and demand they support the appeal: board.of.supervisors@sfgov.org.

Susan Vaughan is the chair of the Sierra Club San Francisco group. Bob Planthold is a disability advocate. They have filed the challenge to the permanent plan.