Secret Service shares more information on safety protocol after crash, retired agent explains variables

MILWAUKEE (CBS 58) -- With more presidential campaign stops coming to Milwaukee this week, we're digging deeper into Monday's crash that involved three vehicles in vice presidential nominee Tim Walz's motorcade.

The Secret Service did not close down traffic Monday, Sept. 2, on the stretch of I-794 where the crash happened. 

About a dozen people were injured, and a campaign staffer was hospitalized with a broken arm.

On Tuesday, the Secret Service shared some more information about their protocol for keeping candidates safe in transport.

A retired Secret Service agent told us it's been a tough stretch for the agency. But he said when there are no surprises, their plans do work.

Retired agent Bobby McDonald said, "The protocols and protective methodologies that the Secret Service use are tried and true."

McDonald served 21 years with the Secret Service, including on details for Presidents Bush and Clinton, and later, then-Vice President Biden.

He said in an ideal scenario, roads would be completely shut down to traffic while a protectee is taken to an event, but several factors come into play.

In a statement Tuesday, the Secret Service wrote, "The Secret Service and its partners base that decision on resources, time of day of the motorcade and the expected amount of traffic on the roads at the time of the movement."

McDonald expanded on the variables, saying, "Are they going to be in a populated area, a residential area? Is it rush hour? A lot of other things go into the decision making."

Walz was driven from the airport to Laborfest at midday on a holiday.

Motorcades require a lot of staffing regardless of traffic closures.

"It is a huge challenge for the Secret Service. They have to work in concert with their police counterparts," according to McDonald.

A spokesperson for the Milwaukee County Sheriff's Office said they had no staffing issues for Monday's event, and they did everything that was asked of them.

And Wisconsin Governor Tony Evers said there were no issues at the state level, either. "We worked with them and did everything that we were asked." He added, "They got everything that they asked for on our part."

In its statement, the Secret Service noted, "Full closures of interstates are typically reserved only for the President of the United States or other protectees depending on extenuating circumstances."

In recent trips to the Milwaukee area, roads were shut down for both Vice President Kamala Harris and VP nominee JD Vance.

McDonald said five or six days' notice is ideal to perform adequate advance security, but he added campaigns often schedule events on short notice, especially as Election Day gets nearer. "Sometimes it handcuffs the police and the Secret Service agents to really be able to do a full, thorough motorcade advance."

Walz's Laborfest appearance was announced three days prior, though it's not known if the Secret Service had been planning for it even further in advance.

On Tuesday, the sheriff's office did not have any additional information on the crash investigation, or the driver involved.

McDonald said, "A lot of times, things happen and we have to be prepared to react to those. And hopefully get our protectees from point A to point B safely and securely."

The Secret Service advance teams are already back to work: both President Biden and former President Trump will campaign in Wisconsin later this week.