Nearly a decade ago, the CTA put in place what the agency said would be a “zero-tolerance” policy barring bus drivers and L operators from using personal cellphones “while on-duty and operating CTA vehicles.”

Announcing the crackdown on distracted drivers and operators in 2009, a CTA official declared, “If an employee is using a personal cellphone while on duty, they will be discharged.”

But the CTA hasn’t backed up that tough talk, a Chicago Sun-Times investigation has found. Bus drivers and L operators have kept yammering away on their cellphones while working, according to agency records examined by the Sun-Times. And they seldom are fired when they’re caught — even in cases where they’ve crashed while talking on a cellphone.

Among the Sun-Times’ findings:

Since 2015, 57 CTA bus drivers have faced disciplinary action after being caught with their mobile devices at work — including what the CTA says were at least two who were on their phones when they got into bus accidents.

Eight of those 57 CTA drivers were texting while driving. Nine were talking on their phones while operating a bus. And 17 of those cases involved bus drivers possessing a personal cellphone while driving — a no-no under the crackdown.

Thirteen of the bus drivers facing disciplinary action resigned or were fired. The rest — including the two drivers involved in cellphone-related crashes in 2017 and 2016 — got lesser punishments, including suspensions and written warnings.

Nine L operators have been disciplined for phone use since 2013, including two who were fired and one who moved to another job “in lieu of discharge.” The rest received lesser punishments that included suspensions and probation.

In the two cases involving bus accidents, CTA spokesman Steve Mayberry says, “I can verify that the operators were using their phones at the time of the accidents. I have no other narrative available.”

One of those crashes happened April 30, 2017, at East 93rd Street and South University Avenue, involving a No. 95 bus. The other, involving a No. 62 bus, happened June 1, 2016, at 55th Street and St. Louis Avenue. No riders were on the second bus, according to Mayberry.

The CTA says it’s “not able to locate any data prior to 2015” relating to bus drivers and cellphone abuses “due to the transition to a new electronic tracking system.”

And Mayberry says he has only “a limited amount of information” on the L incidents. So it’s not clear where they occurred and how the operators were caught.

Mayberry says CTA employees caught for violating the policy on cellphones generally get busted either by supervisors or as a result of complaints from riders.

Among the bus incidents was one last year at Sheffield and Diversey in which a CTA driver was “observed with electronic device” in the ear “and viewing a mobile device while operating the bus,” records show. That driver was given a three-day suspension.

Also in 2017, a bus driver on an express route was “observed talking” on a cellphone while leaving a “terminal and texting while driving.” The driver ended up being “discharged.”

Earlier this year, another bus driver was “observed looking” at a cellphone at 95th and Morgan while in the driver’s seat and “operating [a] vehicle.” The driver was given a “final written warning.”

CTA President Dorval Carter, who reports to Mayor Rahm Emanuel, wouldn’t comment.

Before the “zero-tolerance” crackdown in 2009, when Mayor Richard M. Daley was still in office, CTA rules prohibited the on-duty use of mobile devices for employees in safety-sensitive positions, though workers often were allowed several transgressions before facing firing or other harsh penalties.

The 2009 policy to get more vigilant about cellphones included stricter enforcement and accelerating the disciplinary process. It came after distracted-driving accidents in other public transit systems.

Mayberry says that, despite what another CTA official said in 2009 that workers would be fired for a single cellphone offense, the agency always has used “progressive discipline” under its labor agreements with unions representing its employees.

Robert Kelly, who ran Amalgamated Transit Union Local 308 at the time of the crackdown, says his group, which represents L workers, was encouraging members to keep cellphones in their lockers while working even before that.

“You’ve got to remember, in 2009 when the CTA went wild on this, we were already emphasizing the importance,” Kelly says. “I’d stress . . . ‘Stay off your cellphones, you don’t need them,’ ” so L operators wouldn’t get in trouble and passengers were kept safe.

“It’s just like driving a car: You don’t do it,” Kelly says.

Mayberry characterizes the “incidents of cellphone use by on-duty bus and train operators” as “very rare.” The 66 instances in recent years “occurred over the course of about 24 million combined bus and rail trips,” he says. “CTA training emphasizes the importance of operator focus and attention. Because that training is so strong, the number of incidents is very low.”

Mayberry says the CTA’s policy bars “the use or display of electronic devices by CTA employees while on-duty and operating CTA vehicles, machinery and tools or while employees are in the right of way. This policy allows for accelerated discipline of employees who violate these rules, up to termination.

“Rail operations and rail maintenance employees who possess a cellphone while on duty must have the device turned off and out of view of the public. The only exception to this policy is when rail operations employees cannot establish contact via two-way radio during an incident.”

According to Mayberry, “Reports of bus or rail operators using unauthorized communication devices while on-duty are always investigated thoroughly. When claims of on-duty phone use are proven, the operators are subject to accelerated discipline according to the guidelines agreed to under the collective-bargaining agreement.”

Ken Franklin, the current president of Local 308, says “we support safety” but that the CTA is being “overzealous” in its enforcement.

“We can’t even walk down the platform with a cellphone,” Franklin says.

But he says, “You’ll see managers driving vehicles and using their phones at their discretion.”

Mayberry calls that “yet another unsubstantiated, completely unverified claim with no basis in fact. Any CTA manager that operates non-revenue vehicles or enters the right-of-way is subject to the very same standards to which we hold our bus and rail operators and rail maintenance personnel.”

All CTA employees in jobs in which safety is crucial — not just bus and L operators — are banned from using personal cellphones on duty, but CTA officials say they can’t provide figures on how many other CTA workers have been disciplined as a result of the cellphone rules.