CAMDEN, N.J. -- The Delaware River Port Authority of Pennsylvania and New Jersey has proposed a 67 percent rate increase during the next two years on four toll bridges it operates.

The first increase would go into effect Sept. 14, with the additional revenue to be applied to $1 billion in infrastructure and security improvements over the next five years.

For buses, the initial rate increase will be to $3 per axle, up from $2.25. In 2010, the rate will jump to $3.75 per axle. After that there will be an inflation adjustment every two years.

The four bridges operated by the authority connect Philadelphia and southern New Jersey, and an estimated 55 million vehicles cross them each year.

The money raised by the toll increase will be spent on a number of capital improvements, including redecking, painting and corrosion protection on the Walt Whitman Bridge; painting and corrosion protection on the Benjamin Franklin Bridge, and structural repairs and security improvements on the Commodore Barry and Betsy Ross bridges.

In addition to increased tolls, the authority is also planning to raise fares on the regional transit system (PATCO) it operates, and eliminating or adjusting commuter and senior citizens discounts.

Critics of the plan say that with the increased cost of fuel, bridge users have enough to contend with already. They also point out that in recent years some toll revenues have been spent on economic development projects rather than on infrastructure improvements.

John Matheussens, CEO of the agency, responded that economic development expenditures are authorized by the authoritys charter. However, Matheussens maintains that the additional funds raised by these proposed toll increases will only be spent on necessary investments in infrastructure.

The authoritys board, composed of eight commissioners each from Pennsylvania and New Jersey, will vote on the proposal later this month.