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 (HCTRA) 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.
How it worksEdit
To participate, a driver signs up through the EZ TAG website, via telephone, or at one of the store locations. Next, the customer receives a small, white radio frequency transponder which must be affixed to the inside of their windshield behind their rear view mirror. Finally, when passing through a toll plaza, the driver chooses 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, de-tuning the antenna from its designated frequency, or both, 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.
The new tag uses three different protocols, or communications methods, with the tag readers—ATA, eGo and SeGo.
The protocol used in Houston is ATA for automatic equipment identification; however, a driver in Houston can conceivably use the tag in another state where the other protocols are used. In addition, the tags support ANSI INCITS 256-2001 and ISO 10374. The tag is read by scanners as far as 31.5 feet (9.6 m) at 915 MHz, and the tag features a 2048-bit read/write passive memory.
To duplicate a 915 MHz EZ TAG, a copy of the ROM 2048-bit chip must be dumped and loaded into another ROM chip and a matched inductance of the RFID EZ TAG surface needs to be constructed. Blank 915 MHz RFID pads can be bought online.
As of January 2008, three different sets of EZ Tags have been released. The differences are purely cosmetic.
Despite the similarity in the names, EZ Tags are not compatible with the E-ZPass system in the northeast U.S.
EZ Tag by BancPassEdit
In November 2015, HCTRA announced a new Cash Reloadable EZ Tag. The EZ Tag by BancPass can be reloaded with cash at major retailers, or the user can reload online using a debit or credit card. The EZ Tag by BancPass also differs from the standard EZ Tag by not reloading automatically. The user is notified when the account balance gets low, and the user can choose when and how much to put on the user's account.
The EZ Tag by BancPass is available online, at H-E-B grocery stores and at Corner Store by Valero. Accounts can be reloaded online or at any H-E-B, CVS or Corner Store by Valero.
- 2003, Texas Department of Transportation (TxTag) and NTTA (TollTag)
- On May 17, 2017, Kansas Turnpike Authority (K-TAG) 
- On May 7, 2019, Oklahoma Turnpike Authority (PikePass)
- Speculated: Around early to mid-2018, although as of May 2019, it is not yet interoperable with the toll-roads in Florida (SunPass)
- Speculated: Around early to mid-2018, although as of May 2019, it is not yet interoperable with the toll-roads in Georgia (Peach Pass)
- Speculated: Around early to mid-2018, although as of May 2019, it is not yet interoperable with the toll-roads in North Carolina (NC Quick Pass)
- Speculated: Around early to mid-2018, although as of May 2019, it is not yet interoperable with the toll-roads in South Carolina (Palmetto Pass)
- EZ Tag is not compatible with transponders from the E-ZPass System, although the two companies have been in talks with each other. 
- E-ZPass used in 14 states, mostly in the East, as well as in Ontario
- Fastrak used in California
- GeauxPass used in Louisiana
- I-Pass used in Illinois
- K-Tag used in Kansas
- NationalPass provides interoperability with TransCore systems outside of Texas
- Peach Pass used in Georgia
- Pikepass used in Oklahoma
- Sunpass used in Florida
- Texas tollways
- Business Wire: TXDOT selects TransCore RFIDs
- Design of a UHF RFID Antenna
- WavStore Archived 2013-01-21 at Archive.today
- Begley, Dug (June 19, 2016). "Local toll tags going national, eventually". Houston Chronicle. Retrieved September 23, 2016.
- Kansas Turnpike Authority. "K-TAG compatibility expands with Texas" (PDF) (Press release). Kansas Turnpike Authority. Retrieved May 18, 2017.
- Bora, Abby (June 28, 2017). "Mobility Authority: TxTag will work on toll roads in Florida, Georgia and Carolinas next year". Retrieved June 29, 2017.