Keynote Session 3 — Nikolas Geroliminis

Abstract

Human mobil­i­ty in con­gest­ed city cen­ters is a com­plex dynam­i­cal sys­tem with high den­si­ty of pop­u­la­tion, many trans­port modes to com­pete for lim­it­ed avail­able space and many oper­a­tors that try to effi­cient­ly man­age dif­fer­ent parts of this sys­tem. New emerg­ing modes of trans­porta­tion, such as ride-hail­ing and on-demand ser­vices cre­ate addi­tion­al oppor­tu­ni­ties, but also more com­plex­i­ty. Lit­tle is known about to what degree its oper­a­tions can inter­fere in traf­fic con­di­tions, while replac­ing oth­er trans­porta­tion modes, or when a large num­ber of idle vehi­cles is cruis­ing for pas­sen­gers. We exper­i­men­tal­ly ana­lyze the effi­cien­cy of TNCs using taxi trip data from a Chi­nese megac­i­ty and an agent-based sim­u­la­tion with a trip-based MFD mod­el for deter­min­ing the speed. We inves­ti­gate the effect of expand­ing fleet sizes for TNCs, pas­sen­gers’ incli­na­tion towards shar­ing rides, and strate­gies to alle­vi­ate urban con­ges­tion. We observe that, although a larg­er fleet size reduces wait­ing time, it also inten­si­fies con­ges­tion, which, in turn, pro­longs the total trav­el time. Such con­ges­tion effect is so sig­nif­i­cant that it is near­ly insen­si­tive to pas­sen­gers’ will­ing­ness to share and flex­i­ble sup­ply. Final­ly, park­ing man­age­ment strate­gies can pre­vent idle vehi­cles from cruis­ing with­out assigned pas­sen­gers, mit­i­gat­ing the neg­a­tive impacts of ride-sour­c­ing over con­ges­tion, and improv­ing the ser­vice qual­i­ty. We are also devel­op­ing dif­fer­ent type of con­trol strate­gies, such as relo­ca­tion of emp­ty vehi­cles, park­ing man­age­ment and pric­ing incen­tives to alle­vi­ate the neg­a­tive effects.