Study: On-Demand Mobility Could Clog City Centers

Self-driving vehicles will add, not subtract, from urban traffic congestion unless cities encourage ride sharing, according to a study of traffic in Boston.

So-called mobility-on-demand could capture 40% of trips in urban centers, reducing the use of personal cars or mass transit by 14% each, according to a study by the World Economic Forum, Boston Consulting and the city of Boston.

The report says robotic taxis, shuttles and other on-demand options eventually will handle one-third of trips in greater Boston compared with 7% today. The study calculates similar increase in Berlin and Shanghai.

But adoption will vary sharply by neighborhood, depending upon demographics, availability of mass transit and average trip duration. In general, shorter trips spawn greater interest in robotic shuttles.

The research predicts that a widespread shift to automated vehicles would reduce the number of vehicles on the road across greater Boston by 15%, lower travel time 4%, increase the distance traveled per trip by 16% and slash the amount of parking spaces needed by nearly 50%.

But within the city center, on-demand rides will produce an upswing in traffic. The study says congestion and travel times each would rise 6%. Cities could ease the problem by adopting an occupancy-based pricing plan that discourages riding alone, the report says.

The analysis also suggests considering autonomous-only traffic lanes, converting on-street parking to additional travel lanes or turning on-street parking to dedicated pickup and drop-off areas.