Set 3-6. BYPASS SYMBOLS
When the symbol for a bridge, tunnel, or other possible obstruction is shown, a bypass symbol may placed on
the shaft of the arrow showing whether bypass is easy, difficult, or impossible.
The bypass symbol is placed on the _________________________ __________________________________
_____________________ of the bridge or tunnel symbol.
NOTE: Track one way or two way can never be higher than wheel.
(location; shape) (3-92)
Before proceeding, refer back to Frame 3-57 and briefly review obstructions. For tunnels and overpasses, we
are concerned with reduction in traveled way widths, and less than minimum overhead clearances.
The minimum overhead clearance is __________________________________. The minimum road way width
for two way tracked vehicle traffic is _______________________________ ; for two way wheeled vehicle traffic it
is ________________________ ; for one way tracked vehicle traffic it is _______________________ ; for one way
wheeled vehicle traffic it is ________________________ .