Fleets, construction companies and others with mobile assets already use 1.9-million GPS/wireless devices to remotely monitor their vehicles and field workers, but that number is expected to reach 5.8-million by 2009, according to a new study.

Much of that growth will be fueled by widespread availability of low-cost cell phones and other hand-held devices with integrated GPS, according to the “2005-06 Mobile Resource Management Systems Market Study” released by C.J. Driscoll & Assocs. of Los Angles.

The study projects that by 2009, more than 2-million such devices will be used by fleets and others for dispatching, tracking, customer service and time management.

Automatic vehicle location (AVL) is currently the largest single application for wireless mobile management systems, with 1.3-million U.S. fleet vehicles now equipped with those devices, according to the study.

While GPS-equipped handsets should lead growth over the next four years, the study predicts that installed AVL systems will also grow as some fleets continue to favor vehicle-based monitoring.

In particular, trailer tracking installation has already doubled over the last two years and is expected to continue growing at a strong rate.