According to NYC-DOT (PDF), the average number of vehicles entering Manhattan's CBD every weekday has dropped slightly from 778,000 in 2010 to 731,000 in 2013 (the latest data available). But even with fewer vehicles, average traffic speed has slowed from 9.35 mph (2010) to 8.51 mph (2014). That may not sound like much, but when almost three-quarters of a million vehicles are trying to move, even small losses in average speed have big effects. (You can see NYC's urban mobility scorecard (PDF)," calculated by Texas A&M's Transportation Institute, and compare it with other Eastern cities.) According to one study (PDF), congestion costs NYC about $16 billion a year in productive time lost during commuting. Also, vehicle emissions are a major source of pollution, as the City is trying to cut 80% of its greenhouse gas by 2050.
What to see lots of data on persons and vehicles entering the CBD over time? Go NYMTC online and select Data & Models, then Hub Bound Travel.
Of course, not all vehicles entering the CBD are personal automobiles. (You can read and talk about the impact of other kinds of vehicles in Topic 2 - e-hail and FHVs and Topic 3 -Trucks, buses, etc. But private vehicles get a lot of attention when it comes to reducing congestion because they're the least efficient way to move people in and out of the City--especially when the car is carrying only 1 person.
The next two subtopics of this post discuss ideas for reducing the number of private vehicles in Manhattan, but maybe it's important first to know more about why people are driving into the City. Using census data, a recent study found that commuters who rely on private cars tend to be either (1) from middle- to high-income households with poor public transit options (e.g., Staten Island; eastern Queens), or (2) from middle-income households with average public transit options. (The same study found that other medium and high household-income commuters tend to use a combination of public transit and taxi or e-hail services like Uber. See Topic 2 - e-hail and FHVs) to discuss these services. Low-income households use public transit where it's available--and are just out of luck where it isn't).
►If you drive to and from Manhattan for work, why do you chose to drive? Have you considered other forms of transportation? What would make you switch?
► When government officials are thinking about solutions to congestion, what factors do you think are most important, e.g. length of travel time, reasons for driving, access to public transportation?