Dallas Phasing With Doghouse Configuration - Lag Left-turn

The lagging left-turn does not have a "yellow trap" problem like the leading left turn display. However, lead/lag phasing may vary during the day such that a leading left-turn display in one time period may be lagging during other periods of the day.

An alternative to the Dallas Phasing was developed in Arlington, Texas and is sometimes called the "Arlington Phasing." The Arlington Phasing uses the same Dallas Phasing, except that the lagging protected left-turn direction does not receive a permissive interval during the leading direction protected interval. This permissive interval is excluded for two reasons. First, the permissive direction is usually facing an opposing through queue that is just starting to dissipate, making it unlikely that the permissive left-turn maneuver can be made safely. Second, some practitioners believe that the display of the permissive interval without the same-direction through traffic receiving a green ball is confusing to motorists.

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