Traffic Signals & Roadway Design

A solid green ball for a left turn lane denotes a permissive movement that may encounter opposing traffic. When a left turn signal displays a green ball, motorists should wait for an opening in opposing traffic prior to making their left turn. Unless the left turn signal displays a green arrow, the left turn movement is not protected and motorists should wait to proceed through the intersection. The solid green ball is no longer the national standard and is being phased out in favor of flashing yellow arrows.

The Flashing Yellow Arrow (FYA) left-turn display is the new nationwide standard for traffic signal operation. All cities are required to build new traffic signals with the FYA display and to eventually upgrade their existing traffic signals to have the FYA display. A flashing yellow arrow denotes the same situation as the solid green ball, a permissive left turn movement that requires motorists to wait for an opening in opposing traffic prior to making their left turn movement.

When programming the timing of a traffic signal, the first step is to decide on a cycle length. This cycle length is the amount of time it takes for all approaches of the signal to be serviced before beginning a new cycle. It is common practice to give the most amount of time in this cycle to the primary roadway which contains the higher volume of traffic. This practice minimizes stops and delays for the majority of motorists utilizing the intersection which improves air quality, and reduces congestion on major corridors.

The cycle length is also a key component in traffic signal coordination on major corridors. Once a cycle length is decided, that same cycle length in seconds is programmed into every signal on the major corridor. The beginning of the cycle at each signal on a corridor is then staggered to allow motorists to travel the full length of the corridor without stopping. If you are waiting on a side street at an intersection with a major corridor and no vehicles are currently crossing the intersection but the light is not changing to the side street, this is because the primary roadway has not used all of its allotted time within the cycle.

The wait on a minor street will always be less than two minutes during normal traffic signal operation.

Operating traffic signals in flash at night is an option, but the City of Bryan has chosen to operate our traffic signals in “Free” mode at night instead. When operating in “Free” mode, a traffic signal will remain green on the primary roadway until a vehicle is detected on the minor street. It will then quickly switch over to the minor street and clear out waiting vehicles before returning to the primary roadway. “Free” operation begins at most signals within the city at 10:30 p.m.

Yellow time is calculated using a nationwide standardized equation based on the speed of traffic on the roadway. The City of Bryan’s standard for all-yellow time is four seconds.

The all-red time is also calculated using a nationwide standardized equation for a given speed. The City of Bryan’s standard for all-red time is two seconds.

Yes, the City of Bryan Police Department records video at select intersections that are equipped with the correct camera modules. This video is recorded and rewritten on a rolling 72 hour schedule. If a recording is not recovered within exactly three days of it happening it will be overwritten and lost. An open records request through the city secretary’s office will be required to acquire a saved recording.

Yes, pushing the pedestrian button tells the traffic signal you are there so it can provide a “walk” indication. If you don’t activate the pedestrian signal, the traffic signal may not change or it may not provide enough time for you to cross the street.

The white walk symbol is displayed to allow pedestrians to enter the crosswalk. After a certain amount of time, the flashing orange upraised hand appears as a warning to pedestrians who have not yet entered the crosswalk that it is too late to begin crossing the street.

If you are already in the crosswalk, there will be enough time for you to finish crossing the street. In fact, the flashing orange hand is usually accompanied by a number that counts down to show you how much time you have left to cross the street before the traffic signal changes.

The installation of traffic signals follows a nationally standardized process that is outlined in the Texas Manual of Uniform Traffic Control Devices (TxMUTCD). There is a set of criteria that must be satisfied before a traffic signal can be installed, most of which are based on traffic volumes. Not every street can be given a traffic signal, so traffic volumes are a large factor in determining which intersections will be signalized.

In addition, traffic signals must be spaced a certain distance apart in order to function well. The intersection of two major roadways is always assumed to be a future traffic signal location and then other potential locations must be spaced an appropriate distance away. As other traffic signals are added at minor intersections, it further limits the possible location of additional traffic signals.

Finally, the time frame for the installation of a traffic signal is primarily determined by the funding available. The City of Bryan continues to focus most of the available funding on replacement of existing aged traffic signals. New traffic signals will be considered as part of the City’s Capital Improvement Program.

Please call 979-209-5900 and ask to speak to the Traffic Engineer. If the intersection in question is eligible for a traffic signal, it will be added to a list of locations for possible study. A traffic signal warrant analysis of the intersection will be performed to determine whether or not a signal is necessary or if a different type of mitigation will suffice. If a signal or other device is warranted, the intersection will be added to the city’s ongoing Capital Improvement Program. Roundabouts are preferred where appropriate as in the long term they are more economical and safer.

It is not possible to install a traffic signal at every intersection for a number of reasons, so a particular intersection may not be eligible for a traffic signal. If it is eligible, it may take years before it reaches the top of the priority list for installation. At any intersection, we recommend that citizens take an alternative route instead of making a maneuver that makes them uncomfortable. Whether an uncontrolled intersection is a candidate for a traffic signal or not, it may be necessary for motorists to take an alternative route during busy times of the day instead of making a left-turn or going straight across an intersection. For example, motorists can turn right and then make a U-turn at another location.