When south Minneapolis resident Spencer Davis first biked across the newly renovated Mendota Bridge, he noticed the guardrail built to protect pedestrians and bikers from falling into the Minnesota River seemed unusually low. One wrong move and he felt his 6-foot, 2-inch body could go tumbling over the edge.

"It seems like someone could easily go flying over," said the 32-year-old, who was initially excited when the bridge was reopened to bicycle traffic after the construction project wrapped in September.

Davis, who noticed the change on his first ride across the bridge since the new railings were installed, wasn't the only biker nervous about going across the span — which towers over the river and carries state Highway 55 from the Fort Snelling area to Mendota Heights — since it was reopened. Local cyclists have taken to social media airing their concerns, with many noting the new metal rails are considerably lower than the old guardrails. One commenter in a local cyclist Facebook group said they were, "riding on it a few days ago and was terrified. Ended up hugging the car side, with the thinking I'd rather fall into the highway than off the bridge."

In a thread on Reddit with more than 100 comments, many users said they were uncomfortable crossing the bridge, with one posting: "I made the mistake of commuting home via this bridge rather than an alternate route shortly after it reopened when wind gusts were over 25 mph. Absolutely terrifying."

According to MnDOT spokesperson Anne Meyer, the goal of the $7.07 million, multiyear Mendota Bridge construction project was to improve the smoothness of the span, restore pavement and replace the lighting and railings, which were at the end of their usable life and would no longer be safe.

The Mendota Bridge is on the National Register of Historic Places and is significant for having been the longest continuous, concrete arch bridge in the world when it was built in 1926, according to the Dakota County Historical Society. Its original railing height was 42 inches, but when the bridge was rebuilt and widened in 1992, the railings were raised, Meyer said.

The recent renovation lowered the railings back to their original height of 42 inches. Guidelines on MnDOT's website recommend guardrails on bridges be 54 inches high.

Bicycle Alliance of Minnesota, an advocacy and education group, raised the issue to MnDOT on Oct. 9, said Michael Wojcik, executive director of the nonprofit. "The railings should be higher," he said. The organization has yet to hear an official response from the agency.

The discovery also prompted the nonprofit to look at other bridges they felt were too low, like the Ford Bridge that links the Minneapolis Hiawatha neighborhood to St. Paul's Highland Park.

Non-vehicular cyclist deaths on bridges are rare. In 2014, a retired doctor died on a Minnesota mountain biking trail after he slipped off a bridge he was crossing. The bridge had no guardrails, and was designed to help bikers cross a small stream.