New road construction projects, a steady growth in the economy, and shifts in populations are generating more and more one-call ticket requests for locating utilities' underground lines. Whether a utility chooses to outsource line locating or maintains an in-house underground locating department, these increases are having a significant impact on field operations' manpower and budget numbers. The bottom line is to prevent utility hits.

CenterPoint Energy (Houston, Texas) — formerly Reliant Energy — receives almost 800,000 requests for locates a year. With a service area of more than 5000 sq miles, delivering reliable electric power to more than 1.82 million metered customers, including the city of Houston, is a major task.

So, how does a utility keep up with the continued growth in ticket requests? CenterPoint Energy has developed an effective ticket-screening program, which includes state-of-the-art computer-based, side-by-side comparison of locate tickets and utility mapping. This advanced screening method is dramatically reducing the number of locate-request tickets given to field locators.

Filtering Out

Screening out bad locate-request tickets before dispatching them to field locators has been a core function of CenterPoint's underground locating department for years. The department looks at the address and description on a locate request and compares that request with a map of the area. For example, if the request states that the work is in the front of the house repairing a water line and the electric is in the back or overhead, the ticket is either filtered out or not sent to the field.

Twenty years ago, this screening was done by comparing paper locate tickets with paper maps. Today, CenterPoint screeners use GIS mapping software that integrates with one-call notifications. Screeners are able to compare electronic tickets with electronic maps on the same computer screen.

This last step, comparing the locate ticket to the utility's infrastructure maps on one screen, is where CenterPoint Energy has made the most gains in the underground locating process. The process seems simple now, but when it was first installed, it involved long hours and hard work to integrate the diversity of network architectures — mapping, laptops in the field, third-party locators, the state's one-call system and in-house locate ticket management. The immediate benefit of converting to digital mapping and electronic ticket management was the fact that the hardest part of the process — ticket entry — is already done by the state's one-call center.

Streamlining Call Notification

In CenterPoint's Texas service territory, the state's one-call notification center receives the call from the excavator planning to dig around the electric company's underground lines. Call center staff enter the information in a mapping-based data file, which is sent to the utility. Thanks to the Internet, the call center's computer can communicate with the utility's computer network. Once the ticket request has been entered, it can automatically be downloaded into the utility's database.

As electric companies and one-call centers adopt the latest in mapping technology, automated ticket management systems are becoming a reality. Many one-call centers also are now able to provide additional information, such as GPS map coordinates, that correspond with the locate request.

The main advantages of computer-based ticket management are the increased accuracy of the information being captured and, more importantly, the ability to verify the proposed dig site on a map that shows if there are utilities in the area. It is now part of many one-call centers' policies to find the location while the excavator is on the phone, or as soon as the request is received by the call center.

This results in a more precise determination of which utilities are affected and need to be notified. Pertinent information is typed into the computer as the excavator gives notification of his or her plans to dig. The call attendant entering the information can verify the location on digital maps as he or she is entering the ticket request. Once entered, the map coordinates can be noted and sent with the request for locate notice to the utility.

Bad Tickets

Getting accurate and complete information on locate tickets from the one-call system is a key ingredient in controlling the number of locate requests sent to the field. In Texas, CenterPoint participates on operating committees and has a representative on the state's one-call board of directors. Getting more precise locates is important not only to the utility company trying to locate its underground lines but also to the excavator, and is a major factor in damage prevention. With the installation of mapping software and electronic locate tickets, the ability to compare with a map the one-call center's locate ticket with the utility's mapping, has made screening tickets much easier.

Another major benefit of being able to view the locate ticket and the utility's maps at the same time is that the screeners can more readily catch bad addresses and nonexistent addresses before the tickets are sent to the field. In many cases when this happens, the screener calls the excavator to get better directions or a more accurate address. Without this improved process, field locators typically find they have a bad address after having already spent valuable time traveling to the street with the bad address and driving up and down it looking for the nonexistent address, and finally resorting to calling the excavator to get the right address.

If the new address turns out to be outside the locator's assigned area, even more time is wasted getting the locate ticket to the correct person. CenterPoint screeners have eliminated much of these dry runs by making a few phone calls and having the excavator contact the one-call center with the proper address. The locator only receives the corrected locate ticket.

Each of CenterPoint's screeners look at around 250 electric tickets a day. The total number of ticket requests received averages between 1500 to 2000 electric tickets a day, or approximately 400,000 electric tickets a year. Of that total, about 60% are screened out. CenterPoint Energy does not own the service drop to the house, so some of this reduction is due to jobs like new swimming pool installations, where the work is not in the utility's easement and CenterPoint does not locate the drop.

Screening Rate

CenterPoint also owns the gas distribution system in Houston, including the gas service line. The screening rate for the gas division averages 29%. Therefore, depending on how much aerial lines a utility has, the reduction in the number of locates that are screened out is somewhere between 29% to 60%.

CenterPoint calculates the savings by first taking the daily average number of electric tickets divided by 250. This determines how many screeners are required. Next, multiply the number of screeners by the cost of the average office worker. This is the screening expense. Next, multiply the number of locate requests by the screening rate — 29% to 60%. This gives you the number of locates that won't be sent to the field. Finally, assuming you use a third-party locate contractor, multiply the screened tickets by your per-ticket locate charge, and then subtract the cost of screening. This is the total savings.

CenterPoint Energy estimates that better screening is saving the company about $2 million per year for the electric utility. Since CenterPoint Energy is a combination electric and gas utility, this number is understated because screening is done for both gas and electric locate ticket requests at the same time with the same work force.

Locator-at-Fault Damages Are Dropping

More effective screening is just one benefit of having a locate ticket and map on the same computer screen. All of CenterPoint's field line locators, both in-house and contractor, use CenterPoint's ticket-tracking software on a laptop that combines a ticket and a map. The benefits are significant. The locator is now forced to review the ticket before every locate. At-fault electric and gas damages fell 20% when comparing 2003 with 2004. A new incentive program also was added in the current contractor locator's contract, which helped reduce the number of at-fault contract locating damages.

Having a map co-located on the computer with every locate ticket also speeds up the locate time in the field. Fundamentally, personnel have found that a locate is faster and smoother if the locator has an accurate map versus not having a map and blindly trying to locate the underground electric lines. Speed and accuracy are two big advantages when providing a locator a ticket and a map on the same computer screen.

CenterPoint's screeners and locators use the same database to process locate tickets. CenterPoint's screeners improve the coordinates on the locate tickets sent to the field. In many instances, they center the map right on the house or backyard of the excavation. This means the line locators spend little time panning and zooming to find the right location on the map. The screener has already found the best coordinate that corresponds with the locate ticket.

In the future, CenterPoint Energy envisions using GPS or other technology to work in real time. As the locate tickets come in for screening, they could be dispatched to a locator based on his or her present location. In theory, a locator could go into a large new subdivision, perform two or three locates and, before they leave the subdivision, receive one or two additional tickets that have just come in. Once you can combine ticket locations with facility maps and the location of your locators, more efficiency can be gained.


A key ingredient in addressing the growing number of locate requests is having a complete, accurate and current GIS database. For most utilities this may not be the case. A partial application of this technology may be used with the current GIS information. An electric utility can then invest in improving its GIS data through improved mapping processes and pay for the investment from savings incurred by screening more locate requests and sending less locate tickets to the field. As the utility's GIS maps become more accurate and up-to-date, additional efficiencies for the company are gained. The end result is fewer truck rolls, lower maintenance costs and a lower number of outages due to hits.

Joseph Berry is the underground locating department manager at CenterPoint Energy. He became involved in the damage prevention industry over 20 years ago as a contract locator and has held various positions throughout his career. Berry represents CenterPoint and the electric industry on the Texas One-Call Board and is an active member of the Common Ground Alliance and the Houston Utility Coordinating Committee.