Gwynn's family, including his widow Alicia Gwynn, daughter Anisha Gwynn Jones and son Tony Gwynn Jr. were on hand for the unveiling of the signs at the event.
Local and state officials were at the ceremony, including Assembly Speaker Toni Atkins, Assemblyman Brian Maienschein, County Supervisor Ron Roberts and Caltrans District Director Laurie Berman.
"It's special for me, personally. It brings back memories of me and my dad going to the baseball field and coming back home," Gwynn Jr. told Fox 5 San Diego.
Gwynn Jr. played for the Padres from 2009-2010.
Oddly enough, the Ted Williams Parkway exit -- named for another Hall of Famer and native San Diegan -- is located in the middle of the Gwynn freeway segment.
Gwynn Jr. told San Diego Union Tribune reporters Monday that his father would take that exit, even though it wasn't the fastest route to their home in north Poway, where they lived for 30 years. Gwynn and Williams were good friends before Williams passed away in 2002.
The Union Tribune also reported that the funding for the signs was $8,000 and was approved by the County Board of Supervisors.
"Tony was an important part of our community for so many years," Roberts told the Union Tribune. "He exemplified what a professional athlete should be. You didn't hear about Tony getting in trouble. You didn't hear about Tony wanting to jump from this team to another team. Tony was committed to San Diego, and we feel really honored to be able to do something to really recognize him."
Gwynn, who spent all 20 seasons of his career with the Padres, was elected into the Baseball Hall of Fame in 2007, his first year of eligibility.
Gwynn's stellar statistics -- his 3,141 career hits, .338 batting average, 15 All-Star Game appearances and eight batting titles -- made him a lock for baseball's shrine to greatness.