Up until about 15 years (or so) ago, there were several carloading companies in the area who dealt in LCL or pool car freight such as Haslett Warehousing, Guerin Drayage, Triangle Trucking and several others. There was a lot of truck traffic (I was one of them) in and out of that area. With 4th St. blocked, a lot of traffic was forced over onto 3rd St. or down to 16th. Around 4pm, that area could be a mad house just getting around. After 4th was open all the time, it got a lot easier.

As the Mission Bay and China Basin areas developed, most, and by now all, those companies moved to less expensive real estate or just plain went out of business with the onset of dergulation.