KEY BISCAYNE (CBSMiami) –Modifications to three bike lanes on the Rickenbacker Causeway scheduled to get underway Tuesday to make them safer for cyclists have been delayed.

Due to the rain and upcoming holiday weekend, the modifications are now scheduled to begin on May 30th.

When they do begin the existing bike-lane striping on the William Powell and Bear Cut bridges will get a second white line with “vibratory ridges” to the outside to create a larger buffer between bicyclists and drifting motorists, according to CBS4 news partner The Miami Herald. Unlike rumble strips, the vibratory ridges are placed 30 inches apart to allow cyclists to maneuver in an out of the bike lane if encountering debris or obstacles.

A second white lane will also be added to the West Bridge, which connects the toll booths on the Miami mainland to Hobie Beach.

The modifications are part of several promised safety improvements after two cyclists were fatally struck while riding on the bridge.

Triathlete and businessman Aaron Cohen was killed when he was struck from behind by a hit & run driver February 15 while riding with a companion. Michele Traverso, 25, was arrested and charged in Cohen’s death.

In January 2010, Christophe LeCanne was also struck from behind by a hit & run driver while riding on the Rickenbacker.

Carlos Bertonatti was arrested and charged in LeCanne’s death. He is still awaiting trial.

CBS4 news partner The Miami Herald contributed to this report.