Tarneit is mostly used as agricultural grazing land, but this is changing due to urban sprawl coming from nearby suburbs, such as Hoppers Crossing and Werribee, happening mostly in the southern region of Tarneit.Tarneit's population in 2006 was 7,613, it is estimated to be 19,435 in 2011 and 63,512 in 2031 a rapid increase of 8.9 percent or 55,899 persons. Tarneit already has a secondary school within its boundaries, known as Thomas Carr. A lot of residential growth is occurring in the Thomas Carr district, with other schools and shopping centres planned for construction. Wyndham Village Shopping centre, in the suburb's south, was completed in 2005 to serve the exploding population in the immediate area, especially in the residential developments of Tarneit Gardens, The Rise, Rose Grange and Seasons. Existing Bus Routes in the area have recently been altered and now better serve the suburb.
The New tarneit rail station will be built along Leakes Rd and provide a much faster rail route then current Werribee services which must pass though Altona and Footscray. This will ensure Tarneit becomes a prime regional area for those who comute to the city on a regular basis.Work will start in 2010 on the A new school in Tarneit. Tarneit College as it will be known will provide from grades 10-12 in stage one with construction due to be complete by 2012. The new school will be built on the allocated land in Tarneit Gardens.