The field of transport infrastructure in Poland has a lot of branches which require scientific development. One of the main targets is the protection of natural environment demanding an introduction of numerous new measures in the already existing objects as well as including them in the newly designed ones. More and more commonly, numeric methods are applied for the design of transport infrastructure and monitoring of different types of natural areas. These methods, however, demand a vast amount of empirical data which are not always available.

The present article includes an analysis of three factors threatening natural areas and welfare of living organisms: acoustic pressure level (noise), contents of selected heavy metals in soils as well as levels of emission and imission of selected toxic compounds in the atmosphere. Furthermore, an assessment was made of the influence traffic intensity as well as velocities of the driven vehicles on the pollution of the Roztocze Natural Reserve environment along transport lines (both road and railway ones).

Comprehensive research on the above-mentioned issues has allowed to extend the knowledge applicable both for infrastructure designers and for naturalists taking care of the natural reserve objects and their proper functioning. Moreover, introduction of adequate pro-ecological solutions, after previous recognition of the effect of transport lines on the surrounding area, will allow to reduce degradation (in the already existing objects) and to keep the natural values (in the newly designed ones).