It is difficult to put in perspective the extent of road-building being pursued under the £40 billion National Development Plan. It involves telescoping a previous National Roads Authority's 21-year road-building plan into a seven-year programme, running to 2006. Every major city is to be linked to Dublin by motorway.
Some £4.7 billion is allocated to developing national roads and £1.6 billion to non-national roads. Unfortunately, roads are not natural phenomena. There are obvious potential downsides, according to UCC scientist Mr Gerard Morgan.
"New roads weave across the landscape chipping away at our natural and cultural/archaeological heritage. Meticulous planning is required to avoid loss, damage or fragmentation of valuable habitats including wetlands, woodlands or species-rich grasslands."
Moreover, the pollution threat from roads is linked to the level of vehicle usage, though this is a complex relationship. In 1987, there were 55,814 new passenger car registrations in Ireland - by 2000 that figure had risen to 230,840.
There has been no systematic research of the potential environmental impacts of what is known as "contaminated road drainage" on receiving lakes, rivers, and streams, which are especially vulnerable. A research team at UCC, funded by the Higher Education Authority, is to investigate this problem.
The three-year RUNTOX project will be undertaken in UCC's new Environmental Research Institute (ERI) - a collaboration between the departments of zoology and animal ecology and of biochemistry.
Drainage is a critical factor at three levels. Firstly, at the planning stage it must be taken into account in the design and routing of roads. Secondly, at the construction stage, effective site management is needed as massive amounts of earth are cleared and chemical spillages can easily occur, notably of oil. Thirdly, as a road becomes operational, the question of "routine run-off" arises, particularly the quantity of it.
Once a road is in place, research indicates that with little traffic there are few pollution problems.
Pollution comes in a number of forms. Aerial emissions include greenhouse gasses and a range of hydrocarbon by-products of incomplete fuel combustion and fuel additives. Discharges into water are derived from the accumulation of "vehicle-derived emissions" on the road surface as well as from wear and tear to the surface.
Does Ireland's high rainfall compound road-related pollution? This is not necessarily the case, said Mr Morgan, who is based in the ERI. The key factor seems to be traffic volume and whether a road is in an urban or rural area.
Aerial deposits, including greenhouse gases, on roads may also be a significant contributor to pollution risk. "In some respects, high rainfall can be good. It helps dilute (pollutants) but it's a complex issue," he explained.
With such an unprecedented programme of construction, it is to be expected significant pollution will arise. But research has not fully teased out the complex relationship of factors that determine the ultimate effect on the environment of a major road construction project, Mr Morgan noted. RUNTOX hopes to rectify this.
Lead was the big problem in the past but banning it from petrol has meant other heavy metals such as zinc, copper and cadmium are the concerns.
Hydrocarbons, including oils and greases, can have severe toxic effects though levels are generally low. Nonetheless, they tend to be persistent and don't break down easily in the environment.
The solution, Mr Morgan believes, is in technology involving sedimentation or filtration of water coming off roads. Irish design up to now has concentrated on getting water off carriageways to reduce the risk of flooding or skidding. "Pollution was not seen as of major importance and, in most cases, it probably was not."