San Diego's roadway system provides an extensive network of routes for travel by bicycle. The dry and mild climate of San Diego makes cycling a convenient and pleasant year-round option. At the same time, the city's hilly, canyoned terrain and significantly long average trip distances—brought about by strict low-density zoning laws—somewhat restrict cycling for utilitarian purposes. Older and denser neighborhoods around the downtown tend to be friendlier to utility cycling. This is partly because of the grid street patterns now absent in newer developments farther from the urban core, where suburban style arterial roads are much more common. As a result, a vast majority of cycling related activities are recreational.