The following map has detailed info for all Arlington parade participants. The important info for you will be the drop off or parking areas. You can click on the colored lines for more info. The blue A-B line is Doug Russell Street, the drop off area.
from the parade webiste:
For the past several years we have had traffic backing up on Cooper Street with people trying to drop off Parade participants on the morning of the 4th. The Arlington Police Department and the 4th of July Association feel that this creates a hazardous situation. Therefore we have created a drop-off area on the south side of our staging area. In addition we have shuttle buses running from UTA Maverick Stadium to the south dropoff area. The shuttle buses will begin running at 6:30 am and will be running after the parade to return to Maverick Stadium. We encourage you to make use of the shuttle and dropoff areas.
There will be no dropping off on Cooper Street — the Arlington Police Department will strictly enforce this with no exceptions!
South Drop-off Area: From Park Row Dr., go north on Cooper St., turn right on Doug Russell Rd. Police and event staff will direct you to the drop-off area. As you drop off please help us keep traffic moving by using the designate drop off lanes. You may exit on the south end of the drop-off area where parking is available.