Population trends are a key factor affecting the volume of travel in the region. In addition, where and how people live greatly determines which transportation facilities and modes get used most and which warrant the greatest investment of transportation funding. For these reasons, the NJTPA maintains active programs to monitor and forecast demographic trends. NJTPA uses several sources of such data, including decennial census data (such as journey-to-work), intercensal surveys (such as the American Community Survey), and demographic forecasts.
Available data on NJTPA demographics have been divided into two sources: Forecasts and Census demographics.
The NJTPA Regional Transportation Plan adopted in 2009 describes regional demographics as follows (note that the 2010 Census reports that the population of the NJTPA region is approximately 6.6 million):
The region's transportation system serves a growing population. From 2000 to 2008, the 13-county region grew by over 160,000 people to 6.5 million, a 2.6 percent increase. The population increase in recent years has occurred most rapidly in suburban and outlying counties, notably Ocean (11.4 percent), Somerset (9.1 percent), Warren (7.3 percent) and Hunterdon (5.8 percent) counties. Cities and older suburbs in and around the northeast urban core remained relatively stable in population, showing both slight increases and slight declines.
Continued population growth is predicted over the life of this plan. Plan
2035 foresees population in the region growing to approximately 7.8 million in 2035, a net increase from 2009 of 1.1 million people or roughly 16 percent. This will increase travel activity in every corner of the region the NJTPA's Regional Household Travel Survey estimated that each person generates about 3.3 trips per day. Yet some areas will see more of these trips than others will. Recent trends suggest that future population growth will be most rapid in lower-density, outlying counties, where sprawl patterns of development will continue to add to the number and length of auto trips. However, land use policies can affect the course of future growth.