Improvements in porous pavements practice to meet better road safety

In the last 15 years porous pavements have been diffused worldwide. This is because of the great contribution they can give to road safety with a reasonable cost/effectiveness ratio. It is well known that the use of such kinds of pavements rather than traditional ones, ensures great improvements to roads especially from the point of view of safety by: reducing (if not eliminating) aquaplaning, reducing (if not eliminating) splash & spray, reducing light reflection, enhancing adherence, increasing mean travel speeds, increasing rutting resistance, reducing noise, improving driving comfort. It is also known that despite these improvements they traditionally present some disadvantages such as: higher construction & management costs, lower mechanical resistance, higher accident risks due to increased travel speed. Thanks to the experience of 15 years of practice, many different techniques of design, mixing, laying and managing were developed in order to improve porous pavement performances. The paper presents advantages and disadvantages observed in 15 years of practice with porous pavements; new design methods are pointed out with special regard to a new functional design method set up at the Polytechnic University of Bari. It allows the correct combination of thickness/drain spacing of a porous course to avoid surface runoff