EZ Tag

EZ TAG is an electronic toll collection system in Houston, Texas, United States that allows motorists to pay tolls without stopping at toll booths. Motorists with the Tags are allowed to use lanes reserved exclusively for them on all Harris County Toll Road Authority roads. As of late 2003 the EZ TAG can also be used on all lanes of tolled roadways in Texas that accommodate electronic toll collection.

To participate, drivers sign up through the EZ TAG website, via telephone, or at one of the store locations. Next, the customers receive a small, white radio frequency transponder which must be affixed to the insides of their windshields behind their rear view mirrors. Finally, when passing through a toll plaza, drivers choose lanes specially equipped with sensors that can read EZ TAG transmitters and deduct the appropriate amount from their accounts.

Houston Transtar uses EZ TAG sensors, which are placed at numerous points across Greater Houston, for their Automatic Vehicle Identification (AVI) traffic monitoring system. By tracking the movement of individual transponder tags (EZ TAG user vehicles) over the city, the system can generate real time traffic information for use by the general public. The personal information about the EZ TAG customer is not compromised in this process because the EZ TAG database and the AVI system are not interconnected.

In May 2006, HCTRA introduced a new version of the transponder tag. Instead of battery-powered radio transmitters, the new tags are adhesive stickers with a button-sized microchip in the middle of, and a reflective antenna system throughout the tag. These new tags are sold, rather than rented, so they help save money over the life of the tag by eliminating the monthly $1 rental fee. The battery tag's $15 security deposit can be applied to the purchase of the sticker tag.

Removing the sticker after placement has a high probability of either separating the chip from the antenna, and/or de-tuning the antenna from its designated frequency, therefore invalidating the tag for future use. The tag also relies on the windshield for an amplification effect, and its effective range is greatly reduced if it is not mounted on a glass substrate. This range reduction is so much that not having a tag properly mounted will result in it not reading at all in toll lanes.

These characteristics are much different compared to the old battery tags, which would read fine if not mounted properly. As such, some toll patrons attempt to 'hold up' their sticker tags when driving through the toll lanes, and appear mystified when they do not work as their old tags did.

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Wikipedia