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Will Automated Vehicle Technologies Reduce Urban Congestion? Stanley Young, PhD, PE University of Maryland Center for Advanced Transportation Technology
Varying Visions of Adoption • Estimates of when penetration will be great enough to impact performance • Source: FP Think – Effects of Next-Generation Vehicles on Travel Demand and Highway Capacity, Jan 2914
Factors impacting Adoption Rate and Impact • Driver Experience: Stress relief, safety, comfort, and ability to use travel time for other purposes (texting) • Portion of the network over which the AV’s operate • Quality of service by other modes of transport • Vehicle costs / new models of sharing ownership • Legality of use by those otherwise not qualified to drive. • Enablement of remote parking/ vehicle storage
Near Term Benefits of AVs • Less congestion due to less accidents, but not significant capacity increases • Penetration rate not high enough to increase capacity • Benefits in safety: • Better vehicle following • Less crashes • Safety benefits to reduce non-reoccurring congestion • Magnitude up to debate, but measurable
Long Term Benefits (Increased Capacity) With a larger penetration rate literature/research indicates: • Lanes could be narrower or support wider high capacity trucks • Much of the width is needed to accommodate driver behavior • Each lane could support more traffic • Safe driving requires about 9 car length gap resulting in a capacity of about 2200 vehicles per hour per lane • Automated platoon could enable lane capacity of 6000-8000 vehicles per hour per lane Shladover, 2011
Long Term Unknowns for Increased Capacity Freeways Arterials – (getting to urban) • Capacity fundamentally limited by vehicle control • Must manual driving be eliminated • Will merge/diverge and ramps provide practical limits • Can AVL lanes be introduced to capture majority of benefit • Capacity not fundamentally limited by vehicle control / rather signal control • AV provides incremental benefits, though not transformational • Q? How must urban mobility be approached to leverage AV technology
Long Term (Laws of Parking) • Auto-valet parking may do more to change the urban form • Great accessibility • More flexible placement of parking • Less space
Long Term (Laws of Parking) • Auto-valet parking may do more to change the urban form • Great accessibility • More flexible placement of parking • Smaller parking areas Parking Grayfield Development
Long Term Problem • People could theoretically live in their vehicles and have in constantly move • If we follow the same vehicle ownership rates, congestion could get worse • How can we prevent this from happening? Source: NY Times Source: NY Post
Long Term Vehicle Sharing • Why do you need a car? • Shared system (Zip Car) • Taxi like system • Solves parking problem • People still need to get places • ‘Mobility by the Drink’
Conclusions – AV and Urban Mobility • AV will bring a host of new abilities that will impact mobility, and the urban form • Major impacts are debatable • Increased safety, reduction in non-recurrent congestion • Minimal increased capacity on non-freeway facilities • AV networks potential for service enhancements • Latent demand & empty vehicle circulation may overrun increased capacity • Parking and parking management may be significant • AV sharing concepts needed for transformational change • It’s the ‘wild west’ currently, so stay tuned