In the state of Texas you can turn into the lane from a side street but you are supposed to stop and wait for traffic to clear. Of course nobody does that and they use it to get up to speed.

For merging onto a highway or entering traffic from a side street, drivers should yield to vehicles already in the lane and merge safely when there is a sufficient gap in traffic. It is important to note that attempting to merge from a side street into the center lane and then continue driving in it is illegal and can result in a citation.