title: Crowding effects in vehicular traffic.
abstract: While the impact of crowding on the diffusive transport of molecules within a cell is widely studied in biology, it has thus far been neglected in traffic systems where bulk behavior is the main concern. Here, we study the effects of crowding due to car density and driving fluctuations on the transport of vehicles. Using a microscopic model for traffic, we found that crowding can push car movement from a superballistic down to a subdiffusive state. The transition is also associated with a change in the shape of the probability distribution of positions from a negatively-skewed normal to an exponential distribution. Moreover, crowding broadens the distribution of cars' trap times and cluster sizes. At steady state, the subdiffusive state persists only when there is a large variability in car speeds. We further relate our work to prior findings from random walk models of transport in cellular systems.
authors.affiliation: National Institute of Physics, University of the Philippines Diliman, Quezon City, Philippines.
authors.forename: Jay Samuel L
authors.initials: JS
authors.lastname: Combinido
authors.forename: May T
authors.initials: MT
authors.lastname: Lim
mesh_terms: D001334:Automobile Driving; D001336:Automobiles; D016000:Cluster Analysis; D003441:Crowding; D008962:Models, Theoretical; D011336:Probability; D013997:Time Factors