1. World's Shortest Street (Ebenezer Place – Scotland)
2. World's Narrowest Street (Spreuerhofstraße – Germany)
3. World's Steepest Street (Baldwin Street – New Zealand)
4. World's Most Crooked Road (Lombard St – San Francisco)
It was built originally because vehicles could not cope with the 27% gradient so it was suggested that switchbacks of hair pin bends were built thereby making the ascent or descent more manageable. It was also quite difficult for pedestrians to climb as 16% gradient was more manageable.
Note: most people unfamiliar with San Francisco believe that Lombard Street is the most crooked street, but it's not. It's just better known, prettier, and part of a wealthier neighborhood than the actual most crooked street. Vermont Street between 20th St & 22nd St in San Francisco's Portrero Hill district is actually the most crooked. (Thanks, David S.)
5. Most Complicated Interchange (Judge Harry Pregerson Interchange – Los Angeles)
6. World's Longest National Highway (Highway 1 – Australia)
7. World's Largest Roundabout (Putrajaya – Malaysia)
The main reason people don't take note is because they tend to think it is just a hill. The circumferential length of this roundabout is approximately 3.4km, and the road that circumvents it is Persiaran Sultan Salahuddin Abdul Aziz Shah.
8. World's Widest Street (9 de Julio – Buenos Aires, Argentina)
Those with a quick pace and long legs will be lucky if they get to the other side with the changing of two traffic lights that are placed at every intersection. A pedestrian crossing usually requires a few extra minutes and a few green lights. However, the inevitable stop in the center provides a great perspective of the magnitude of the street as well as the city. The street runs far in both directions and connects the unique sections of the great metropolis. Some of Buenos Aires' main landmarks can be seen along the way; most notably, the Obelisk.
9. World's Longest Street (Yonge St – Ontario, Canada)
(Actually, The Guinness Book of World Records no longer lists Yonge as the longest street in the world, citing instead the Pan-American Highway as the world's longest "motorable road").