Public transportation in Albania is mainly characterized by the use of furgons, the equivalent of minibuses, vans or shuttles identifiable by yellow plates. Improvements to the road infrastructure, urban transportation, and air travel have all led to a vast improvement in transport. These upgrades have played a key role in supporting Albania's economy, which in the past decade has come to rely heavily on the construction industry. In recent years, a major road construction spree took place on the main state roads of Albania, involving the construction of new roadways, putting of contemporary signs, planting of trees, and related greening projects. Works on most highways are completed, though they remained unfinished between 2011 and 2013 as per lack of funds. All roads are property of Albanian Road Authority (Autoriteti Rrugor Shqiptar, former Drejtoria e Përgjithshme e Rrugëve) and maintained by Ndërmarrja Shtetërore Rruga-Ura. The government plans to create some toll highways in the near future. Albanian bitumen from Selenicë in Southern Albania is well known for its quality as it has been used on some European motorways.