The Trans-Amazonian Highway ( official designation BR-230, official name Rodovia Transamazônica), was introduced on September 27, 1972, it is 4,000 km long, making it the third longest highway in Brazil crossing part of Amazon rainforest in the east-west direction - because of high construction costs and Brazil financial crisis in the late 1970s, only a short part of the highway was paved - travel on the non-paved stretches of the highway is extremely difficult and dangerous during the region's rainy season between October and March - in the wet season cars often get stuck in the poorly constructed road and in the dry season there are often pot holes in the dry mud roads that damage vehicles.