The man behind the I-95 rebuild

• Carroll sprang into action. He was on the ground within three hours, assessing the damage and employing "emergency triage" to stabilize the situation.

Why it matters: The state transportation boss, who oversees more than 11,000 PennDot workers, hasn't left the collapse site since.

• He's given up his Harrisburg office to camp out in the cramped quarters of a Jeep, which has doubled as Carroll's war room, while crews feverishly reconnect one of the nation's most important transport arteries.
• There, he has coordinated every inch of the rebuild with the help of an iPad and two cell phones that ring off the hook.

Backstory: Carroll is a former state lawmaker who started his political career under former Rep. John Yudichak, then a Democrat representing parts of Luzerne County, and longtime U.S. Rep. Paul Kanjorski, who represented a northeastern pocket including Scranton and Wilkes-Barre.

• He later represented Pennsylvania's 118th District for 16 years before Gov. Josh Shapiro appointed him this year as the state's traffic boss.
• Carroll was instrumental in getting a provision added to a 2014 state law that increased minimum penalties for drivers who left the scene of fatal accidents. He was also honored for his work rehabilitating the Stillwater Dam in Tobyhanna Township.

Between the lines: As traffic returns to the busy I-95 corridor, it appears Carroll has won over Shapiro, a legion of construction and union officials, and the formidable Philadelphia with his calm, no-nonsense approach. His answers about the rebuild have been short, sweet and tempered.

• "Philly people like to have news delivered without any varnish," Carroll told Axios. "Be as honest as you can be and sincere, and they will trust you."

What they're saying: One former colleague described Carroll as a smart and diligent leader in the din of Dale Carnegie. He was usually the one answering the phone at his office when he was a state representative, Robert Durkin, president and CEO of the Greater Scranton Chamber of Commerce, tells Axios. And he makes sure he's certain of things before talking.

• "He's not [just a] politician saying something to appease an audience," Durkin says. "I'm really glad for our sake that he's on the job."

The bottom line: Sustaining himself on black coffee, Carroll tells Axios that he sees his role as a "problem solver," ensuring construction crews have everything they need. Now that one of the heaviest parts is done, Carroll can breathe a little.

• "It's a day to celebrate," Carroll said at the highway's reopening ceremony on Friday, "but the work continues."