The SHIDRA project aimed to mitigate the environmental impact (in terms of air quality and on agricultural soil quality) of the construction of new roads, especially motorways, which cut through rural areas. Located in the Po Valley in Lombardy, the project aimed to create plant corridors along the roadside to act as barriers to ‘trap’ the particulate matter emitted by road traffic pollutants and prevent its diffusion into the wider rural area. The overall objective was to develop specially-designed (based on their geometric shape and mix of vegetation species) dust-trapping barriers along an 8 km stretch of motorway between Val Trompia (in the province of Brescia) and Fascia dei Fontanili in Cremona province. The roof-shaped barriers, built 15-20 metre in depth, would operate both as habitat hedges for wildlife and as an ecological corridor. Results would be monitored and the degree of reduction of pollutants assessed. Best use of financial resources normally paid to farmers in compensation for damages caused by new roads would also be examined. Finally, an experimental field would be established where different kind of vegetation structures (barriers) can be monitored using conventional automatic sampling devices and biological monitoring techniques.