You really should travel the roads between points of work and home during the proper rush hour prior to making a commitment. I do not know if various days of the week make a difference. It does on my drives.

there are daily backups that are never mdntioned in the traffic report. i.e. beltway through tysons in am. outter loop through mont cty in am inner loop in pm. wilson bridge backup on inner loop(no cameras). 295 backup in in am out in pm(no cameras) 66 backups inside the beltway.

took my wife 15-20 min to get out of her parking garage at 14th &L at 5pm.

I also understand the roads just east of IAD are very messy during commute hours.