The most common methods are saltcrete mixed into road asphalt, and simply putting the brine back into the ocean.
Saltcrete asphalt immobilises the brine, which can be environmentally toxic in high concentrations. The quantity of brine released into the ocean increases the overall ocean salinity insignificantly. Although some studies have suggested that under certain conditions, brine can disperse slowly, and form plumes which sink to the bottom.
I would generally support pipelines from the coast, over non-coastal desalinisation facilities. I'd also certainly support studies into brine dispersal. But I tend to think brine disposal is one of the easier commercial-industrial waste problems.