Boston and the larger Greater Boston region are notorious for traffic congestion due to the region's high population density, outmoded highway system, and economic growth resulting in a high concentration of corporations with large offices located along major expressways and urban loops (including Route 128, MassPike, I-93, and I-495). Despite the region's compact nature, inbound traffic becomes very heavy on all expressways as early as 6am on a typical weekday morning, making an inbound drive from the suburbs as long as 75 minutes. Improvements brought by the infamous Big Dig project temporarily improved expressway traffic within Boston's city limits, but traffic congestion soon returned, also appearing in areas such as the rapidly-developing Seaport District area of South Boston.