In the 1950s and 1960s, the arrival of summer meant the adventure of going to drive-in movie theaters.

The screen image wasn’t always as sharp as what you would see indoors, and the sound systems were often a little funky, but there was a wonderful party atmosphere on the grounds of a drive-in that delighted families, as well as privacy in their cars that teenagers couldn’t find anywhere else.

Invented in Camden, N.J., in the 1930s, the development of drive-ins was stalled for more than a decade by the Depression and then the gas shortages of World War II. The boom period eventually arrived during the 1950s, when 4,000 drive-ins opened across the country.

The rise of post-World War II teen culture bolstered the phenomenon because that audience didn’t care so much about what was on the screen — critics called drive-ins “passion pits” — and theater operators could get away with playing cheap, Z-grade fare like “How to Stuff a Wild Bikini” or “Dr. Goldfoot and the Girl Bombs.”

Regular mainstream Hollywood fare was popular at drive-ins, too, especially on the $2 a carload nights that my family used to enjoy in the Philadelphia area. (I never saw anyone pull the stunt of hiding a couple of extra people in the trunk.)

Connecticut once had more than a dozen drive-in theaters. But by the early 1980s venues such as the Pix in Bridgeport and the Red and Blue in Milford closed, along with very popular places like the Danbury Drive-In and the Blue Hills Drive-In in Bloomfield. Across the country, more than 3,500 venues closed.

Cynics have written that many of the drive-ins that existed in the United States up to the 1970s were simply holding actions by canny real estate developers who knew they would eventually make a big profit on the land when suburban development reached outlying areas. That is what happened to all of the drive-ins around Philadelphia that were a part of my growing up years in the 1960s.

Although the United Drive-In Theatre Owners Association reports the number of drive-ins in the U.S. has dropped to less than 400, Connecticut still has three theaters in operation — the Southington Drive-In, the Mansfield Drive-In and the Pleasant Valley Drive-In in Barkhamstead.

It is hard to think of a more enjoyably nostalgic summer jaunt than a visit to one of these throwbacks to an earlier era in pop entertainment. Reminders of a time when entrepreneurs were willing to dedicate 15 acres or more to a business that only operated four or five hours a day, when the weather was good.

I hadn’t been to an outdoor movie theater in more than 40 years, so recent visits took me back to the great fun of watching a movie under a night sky, in the comfort and privacy of your own car. The Mansfield and Pleasant Valley drive-ins have hung on as commercial establishments in slightly remote areas of the state, still packing in cars in for current Hollywood blockbusters such as “Wonder Woman” and “Spider Man: Homecoming.”

The days of those clunky portable speakers hanging on the window of your car are long gone. Most drive-ins now use systems that transmit the sound to car radios.

The great retro feel of the snack bar at Pleasant Valley demonstrates that one of the selling points of these theaters has always been a wider array of food choices than what you would find at a standard indoor multiplex. Maybe because of the picnic atmosphere and the fact that you have to stay up later to see the movies — for much of the summer a drive-in can’t start its first feature until close to 9 p.m. — heartier fare like burgers and hotdogs has always been standard. Believe it or not, in some parts of middle America pizza was unknown until many drive-in snack bars added it to their menus in the 1950s.

The Southington Drive-In is unique in that it is owned by the town and run as a nonprofit. Town Council member Dawn Mecili says after the drive-in closed in 2002, the town purchased the property because it was adjacent to a park.

“We asked if the screen could be saved and it was, but then we had to figure out what we would do with it. I made the mistake,” Mecili says, laughing, “of saying, ‘Let’s run the drive-in as usual to (raise) civic club funds.’ ... I believe it is now the only community-owned and volunteer-operated drive-in (in the country).”

The drive-in is open on Saturday nights from early June through the end of October, and each week a different Southington civic organization runs the place. “All of the money goes back to that host. The groups can raise $2,000 in one night, which is unheard of,” Mecili says.

The revived nonprofit drive-in is in its eighth season and often fills the 430 parking spots for recent and classic family movies such as “Beauty and the Beast” and “The Goonies.”

“We poll our customers and have gotten to know what families want. But teens and adults said they wanted date nights, so we showed ‘Dirty Dancing’ this summer,” Mecili says, along with two other big hits of yesteryear, “Jaws” and “Top Gun.”

“I think you would be challenged to come up with any other way for a whole family to be entertained for 10 or 15 dollars,” she says.

Mecili gets comments all summer from younger people who are thrilled to experience this pop entertainment blast from the past. “As an elected official and a volunteer, it is so endearing and heart-warming to keep the drive-in experience going.”; Twitter: @joesview