Complex sentence: RTD's first light rail line, a section of what is now the D Line, opened on Friday, October 7,1994, with free service for that half day and all weekend, and revenue service starting on October 10.
Split into simpler sentences: RTD's first light rail line, a section of what is now the D Line, opened on Friday, October 7,1994. It operated with free service for that half day and the first weekend, with revenue service starting on October 10.