Fans noticed there are modern yellow lines on a road in 'Bridgerton' even though cars didn't exist yet in 1813

• Fans spotted modern-day yellow traffic lines on the road in the first episode of "Bridgerton," a Netflix original series set in 1813 London.
• Cars didn't exist in the early 19th century, so many viewers pointed out the historically inaccurate blunder.
• People also noticed other minor overlooked details in season one, such as a Primark poster, a manhole, and seedless fruit.

"Bridgerton" fans have identified an overlooked modern-day detail in the period piece's first episode.

Season one of the Netflix original series, which hit the streaming platform on December 25, is adapted from Julia Quinn's bestselling Bridgerton book series and takes place in 1813.

The on-screen costumes, dialect, and customs immerse viewers in show creator Chris Van Dusen's reimagined Regency England, but eagle-eyed fans noticed a glaring mistake in episode one: yellow traffic lines.

Read more: 21 details you might have missed on season one of 'Bridgerton'

As the Featheringtons and the Bridgertons travel to Buckingham Palace in their horse-drawn carriages three minutes into the season, the camera shows that the road outside of Bath's Royal Crescent has unconcealed traffic lines.

Cars didn't exist in 1813 and weren't widely used in London until the mid-20th century. According to Travel & Leisure, yellow traffic lines didn't appear on roads until the 1950s.

So, "Bridgerton" fans pointed out that the on-screen inclusion of the road markings must have been a blunder.

—Fake History Hunter (@fakehistoryhunt) January 24, 2021

—Lane (@laneplants) January 22, 2021

As fans watched the rest of the season, some claimed to notice other minor missteps on "Bridgerton" that didn't exactly line up with the Regency time period.

Viewers said they spotted out-of-place objects like a poster for fashion retailer Primark, a manhole cover, parking signs, a doorbell, and seedless fruits.

Read more: Netflix has officially renewed 'Bridgerton.' Here's what we know so far about the Regency drama's 2nd season.

—Jordan (@JORDANLEWlS) January 5, 2021

—Katy Jon Went (@katyjon) January 24, 2021

—Tom ‍‍ (@Tom_TheSequel) January 3, 2021

Van Dusen hasn't responded to fan's comments about the objects or offered an explanation for the traffic lines.

However, he did reveal that the team relied on technology to create certain scenes on "Bridgerton," which was primarily shot in London and Bath.

Read more: Here's where every major character ended up on the season 1 finale of 'Bridgerton'

For example, Grosvenor Square, a real location in London's Mayfair district, is the center of town on the show. While live-tweeting the first episode after the season premiere, the showrunner revealed that the on-screen version of the square isn't real.

"Our Grosvenor Square is completely fictional. In that it's all green screen," he wrote.

—Chris Van Dusen (@chrisvandusen) December 27, 2020