WIRED ON FRIDAY: By determining what radio stations passing motorists are listening to, the latest digital billboards can target advertisements to suit the audience.

How often have you looked at the billboards erected along roadsides as you drive past or wait in traffic? Like most people, you probably don't pay much attention to them.

What if, however, the advertisement you looked at on a billboard was specifically tailored to your tastes and, therefore, made more of an impression?

Two companies in California have teamed up to introduce digital billboards that can display text and video.

In addition, the advertisements displayed can change depending on who is driving by. This is accomplished by determining what radio stations passing motorists are listening to, which has a hint of Big Brother about it.

A study of 1,000 adults conducted by the Consumer Electronics Manufacturers Association and reported in Media Matters in November/December 1999 said that, of those people who listen to the radio, 59 per cent do so in their car compared with 25 per cent at home and 13 per cent at work.

Using Smart Sign technology, which is installed on each sign, the advertisements on the billboards can change to suit what the person is listening to on the radio whether it is news, sports, weather, country music or rock 'n' roll.

Smart signs have the ability to detect the radio station signals from passing cars and then change the content on the sign to reflect the tastes and buying preferences of the traffic patterns.

The technology does not single out individual cars but rather treats passing cars as a single group and determines overall listening habits.

For example, if the majority of cars passing by are tuned to classical music stations, the billboard might advertise a luxury car while an advertisement for a pick-up truck might be displayed if many of the car radios are tuned to country music stations.

One of the companies behind the business plan is Alaris Media Network, a Sacramento-based outdoor sign company with 10 video screens in California and plans to expand into another 20 major US markets over the next five years.

It has already modified two billboards in Sacramento - the Cal Expo sign on Business Highway 80 and the Roseville Auto Mall sign - and expects to modify more this month.

Each Alaris multimedia Smart Sign is equipped with a perceptive sensor technology called Mobiltrak Full Spectrum, which captures the radio station frequencies of passing cars.

The sensor on each sign picks up the radio frequency of 60 to 80 per cent of all drive-by traffic. The sensor then sends this data to a Mobiltrak repository server in Phoenix, Arizona.

It merges the information with a demographic research database called Media Audit. Media Audit is a research firm that conducts ongoing surveys of radio listeners across the United States.

The demographic information collected by Media Audit provides very specific insights into the preferences and buying habits of many cross-sections of radio listeners in specific markets across the country.

The radio listener information is assimilated with the media audits data in real-time and then the sign is programmed accordingly.

The advertising content has the ability to change many times per minute or every hour to reflect the listening habits of the passing traffic.

Alaris Media and Mobiltrak, a company based in Chandler, Arizona, announced their partnership on this project last November.

Alaris Media provides automobile dealers, casinos, insurance companies, radio and television stations, mortgage companies and banks with media advice and advertising.

Its chief executive, Mr Tom Langeland, said he came up with the idea for digital billboards when the dotcoms began buying up all of the billboard space and drove up the market price of a static billboard by 100 per cent.

"We then saw the possibility of sharing the billboard location between several clients," he said.

Ms Phyllis Neill, chief operating officer of Mobiltrak, says the company has 80 clients in the US, mainly in Phoenix and Houston in Texas.

About 60 per cent of its customers are auto dealers and 40 per cent are a cross section of event venues, destination advertisers and billboard companies.

"The advantage of the Mobiltrak data [is that they are] specific to the geography where the sensor is located.

"Therefore, our clients know that the types of customers pulling onto their lot have vastly different characteristics from the traffic at large and can mine these differences to really set them apart from their competition."

Ms Neill said the partnership with Alaris Media was to "wire" a unit at the location of each of its outdoor electronic LED billboards.

"Alaris Media is able to take the data gathered from these locations, and give potential advertisers real insight into their passer-by customers 'in the wild', to better pinpoint times of day and content advertising," she explained.

As to whether this type of billboard advertising may be seen on your road soon, Mr Langeland, who is originally from Norway, said he had already received some interest overseas to joint venture the technology.

"If we decide to do this, it will be in the form of joint ventures with other media companies," he said.