Traffic Signal Systems
Flashing Yellow Arrow (FYA) Signals
The City of Sugar Land introduced the Flashing Yellow Arrow (FYA) left-turn signal in Spring 2010.
- The FYA indication replaced several protected green arrow left turns, and helped to reduce delay and wait time by as much as 28 percent on major thoroughfares.
- There are 35 traffic signals that have FYA indications on one or more left-turn movements at the signal.
- The FYA signal is disabled when school zones are active and during the walk phase for a pedestrian crossing at a signal.
- Vehicle paths cannot cross each other on opposing left turns.
- There must be adequate sight distance for the left turn movement.
- The posted speed limit must be 45 mph or less.
For all traffic signals in Sugar Land, there are pedestrian signals located on the crosswalks at the traffic signal. These pedestrian signals are based on the latest TxDOT countdown module (which has three parts for pedestrian crossings).
- First Phase - white WALK indication that normally provides 4 to 7 seconds for pedestrians to leave the curb and start crossing the street.
- Second Phase - orange DON’T WALK indication, which informs pedestrians whom are at the curb to not enter the crosswalk (since there will not be enough time to cross).
- Third Phase - a countdown timer will begin, which notifies pedestrians of how many seconds remain to clear the crosswalk.
Signal Detection Systems
Traffic signals use vehicle detection systems which allocate signal timing based on vehicles arriving at the signal. For example, when a vehicle approaches a signal from the side street, the signal system detects it and provides signal timing to this street approach.
The city currently uses two forms of signal detection: inductive loops that are installed in the approach lanes, and camera detection that is placed on the signal arms. Both loops and cameras establish zones that measure the presence of a vehicle and the amount of time the vehicle occupies the zone.
Corridor Signal Synchronization
Traffic signal synchronization is helpful when there is a high number of vehicles traveling along a roadway corridor and are stopping at several signal lights. Signal synchronization improves traffic flow on main corridor direction, but can cause longer delays for left-turning and side street traffic. Therefore, signal timing is calculated so that the signals can turn green before the vehicle group arrives,
and delay is reduced for all intersection approaches.
Synchronization has been implemented in the major corridors listed below. Travel time analyses are conducted throughout the year to maintain synchronization.
- SH 6 (Brooks Street – Frost Pass)
- US 90A (Dairy Ashford – Easton Avenue)
- Sweetwater Boulevard (Alcorn Oaks – First Colony & Colony Square)
- Williams Trace (SH 6 – US 59)
Emergency Preemption Devices
All traffic signals in Sugar Land use receivers for emergency vehicle preemption. These receivers are read by transponder devices that are equipped on all Fire Department trucks and several EMS units. An emergency vehicle (in route to a call) can send a preemption signal to the traffic signal receiver. The traffic signal will then provide a green indication to the emergency vehicle. The signal preemption clears any stopped vehicles and allows the emergency vehicle faster access through the signal. Once the preemption clears, the signal returns to its normal operation.
In addition, traffic signal receivers are routinely tested to ensure emergency preemption readiness as part of our maintenance program.
School Zone Flasher Systems
The City of Sugar Land maintains the flasher warning systems on 32 school zone signs. The school zone flashers are used for 21 designated school zones (serving schools with children walking to and from the school campuses). At the beginning of each school session, the flasher systems are updated with the weekly school schedule, and will operate on such schedule throughout the school year.