Don't cross that white solid line while under the tunnel for ANY reason! There are cameras all along the entire tunnel which will take a picture of your license plate and nail you with a huge ticket!!
Don't play the "hold-your-breath-until-the-end-of-the-tunnel" game or you're bound to suffocate and pass out. This tunnel is a non-stop traffic nightmare and a real bonafide shitshow. EVERY. TIME.
Avoid this tunnel at all costs, take the George Washington Bridge. The GWB is further north but when car breaks down in the two lane tunnel it doesn't get towed out causing a traffic jam for hours!