Page:UK Traffic Signs Manual - Chapter 8 - Part 1 (Traffic Safety Measures and Signs for Road). Designs 2009.pdf/247

DUAL CARRIAGEWAY ROADS

With tidal flow operations, approaching traffic is marshalled into physically divided lanes which then guide the vehicles through the contra-flow. Access to the tidal lane is controlled by four "gates" at key locations. There are two operating conditions for each tidal flow operation depending on the direction of flow along the tidal lane.

Table 6.9 specifies the tidal flow operating conditions. For each condition shown, the first number is the number of lanes running in the primary direction, the second is the number of lanes running in the secondary direction.

NOTE: Partial contra-flow is not operated on two-lane carriageways

In the following figures, the convention is adopted that a gate is "open" if it lies parallel to the carriageway lane lines, and "closed" when it is drawn at an angle across the lane. 246