Some countries are famous for the quality of their roads (and maybe also the speeds you may go on them). According to the Global Competitiveness Report, the UAE boasts the best roads. France, Hong Kong, Japan, Singapore, and Switzerland also have very high-quality roads—with a ‘quality of roads' score higher than 6—and yet none make the top 100 countries by land area and thus all fall outside the group of countries with the largest road networks.

If large countries with expansive road networks struggle to maintain high-quality roads, to what extent is the public maintenance of roadways hampered by corruption? We analyzed data for seven countries, Australia, Brazil, Canada, China, India, Russia, and the United States, which combined account for 70 percent of the global roads network and roughly half of the world's land area.

Four of the seven countries have high road quality, scoring a 5 or greater on the 'quality of roads' subindex of the Global Competitiveness Index in 2017. This means that the length and quality of road network are not correlated. In fact, the data shows there is a slight positive relationship between road quality and length.

All seven countries also have different densities of roadways, which is reasonable given challenging topographies and climate conditions and potentially insufficient investment in infrastructure. But, again, investment issues could relate to corruption.

So, what about corruption and roadways? The data is absolutely inconclusive.