The reason they extended South First to 1626 is not for the convenience of bicyclists, but rather to help facilitate more urban sprawl to the South. Within 6 months of opening, that road will be just as unrideable and dangerous as 1626 is now. If you don't believe me, check out the number of crackerbox K&B, etc. housing developments popping up all over the far South side.
Every person who moves into the these new sprawl neighborhoods, lured by low prices for ghetto-quality construction, will be driving a car for every single trip they make. Need to pick up a loaf of bread? Hop in the SUV and drive 3 or 4 miles to the nearest store. It's too far to bike or walk for most people, and there is no public transportation. Most of these houses will contain 3-4 drivers, each with their own vehicle, an SUV more often than not, and all these vehicles will be used as SOV's - single occupancy vehicles - 98 to 99% of the time.
Because of the extremely large size of the vehicles used and the fact that most of the roads have not been rebuilt to accomodate miles and miles of urban sprawl, these people will spend lots of time sitting in traffic. Since they have to drive every single place they need to go and frequently need to drive a long way, this will make them very irritable and enraged. When they see a bicyclist on the road in front of them, the small additional amount of inconvenience they will experience is enough to make them snap. For once, thanks to their 4000 pound vehicle vs. a 20 pound bike, they are in command. Blinded by the rage built from the frustration of hundreds of hours of sitting in traffic jams, they step on the gas and barrel directly at the bicyclist. They didn't really mean to hit him/her, just scare them a little to make themselves feel better by passing as closely as possible. Unfortunately they miscalculated a little. Bam! There's contact between the side and/or sideview mirror of the SUV and the bicyclist and bicycle and bicyclist goes flying into the drainage ditch at the side of the road.
The driver begins to panic. Oh my god, what to do now? The answer is convenient, simple, and straight-forward: just continue driving as if nothing had happened, leaving the bicyclist's twisted body lying by the roadside. Most people are not psychopaths or serial killers. This particular driver will be wracked by guilt, intensely for a few weeks, and then on and off in the future. He'll almost certainly never hit another bicycle; in fact, will take extra care when passing bicyclists on the road in the future, since every time he sees one he'll be reminded of the blood spattered onto the side of his windsheild from before. Unfortunately, he has thousands of neighbors who think exactly the way he does, who sit in the same traffic jams every day, and experience the same rages. They, too are primed to kill and haven't had the jarring experience of actually snuffing out an actual bicyclist yet to temper their rage. It only takes one of them to ruin your day.