The old U.S. 80 bridge might be unsafe for modern-day vehicles, but it’s been a mighty fine setting for bikes and tennis shoes this year, and its popularity is growing.

Event-goers have either ridden bicycles or walked across the 81-year-old span three times this year, and six more special events are planned before year’s end, making for the most foot and bike traffic ever on the 81-year-old span, superintendent Herman Smith said.

“It never used to be like this,” Smith said during a Vicksburg Bridge Commission meeting Wednesday. “The bridge is getting extremely popular.”

A 5K walk to benefit cystic fibrosis research is set for Sept. 10. The Bricks and Spokes event Oct. 1, put on by Vicksburg Main Street, features rides of 10, 30 and 50 miles. The Mississippi Association for Providing Supports to Employment has plans for a walk on Sept. 17, after postponing it in April when the Mississippi River began its historic spring rise.

Interest in the 1.6-mile bridge isn’t new.

“We enjoy coming to Vicksburg,” said Laurie Martin of Cystic Fibrosis Foundation Mississippi. “The bridge is perfect, and the views are fantastic. How many people can say they’ve walked across the Mississippi River?”

Harry Sharp, chairman of Main Street’s advisory board, said the bridge is the draw and this year’s fall event “combines both the bicycling and downtown.”

Extra insurance must be purchased to cover the riders. The policy must name Warren County and the Vicksburg Bridge Commission as insured entities, commission attorney Bobby Bailess said.

Filling out the rest of the bridge’s busy schedule is the Over The River Run Oct. 8, the Living Independence for Everyone wheelchair event Oct. 29 and Bras for Breast Cancer on Nov. 3.

The bridge was completed in 1930 and purchased by Warren County in 1947. It was closed to vehicles in 1998 with officials saying the roadbed could no longer handle the weight of vehicles.

A year earlier, Kansas City Southern Railway made and rescinded — after a community outcry — a $5.5 million offer to buy the bridge outright.

In 1999, about 60 percent of votes cast in a nonbinding referendum said traffic should return; 34 percent said it should be turned into a pedestrian park, to be funded with a federal transportation improvement grant; the remainder said the county should sell the bridge.

In 2005, the county and its five appointed commissioners agreed again to pursue a federal grant to convert the road into a recreational area — complete with 1,200 linear feet of walking space protected by a 30-foot screen to prevent walkers from flying objects from trains and a two-lane bicycle path on the entire length of the bridge, according to a project description sent to the Mississippi Department of Transportation.

Despite support from 17 public and private entities — including the cities of Vicksburg and Port Gibson, Vicksburg National Military Park, the Mississippi Development Authority and Audubon Mississippi — the project stalled in 2006 when KCS fired off letters to the MDOT, Vicksburg’s state and federal legislators and Gov. Haley Barbour opposing the idea.

KCS claimed a park was too unsafe and violated terms of the company’s lease prohibiting creation of a hazardous condition along the rail.

The railroad and utilities, which have lines attached to the superstructure, pay rent to use the bridge. Fees from tolls and rents have averaged about $1.2 million over the past five years, according to independent audits conducted annually.

An audit for 2011 showed 284,094 rail cars crossed the bridge from July 2010 through June 2011, up about 6 percent compared to the previous year. The bridge’s net assets fell 4.5 percent during the audit period, showing a $257,732 deficit due to more than $600,000 in contract work to repair cracks and re-anchor pier 5.

The bridge has about $5 million in reserve funds, mainly from rail tolls, bridge officials said in July.