A Research On The Traffic Behavior Of Urban Expressway Exit With Additional Lane On Parallel Street

Urban expressways are of suitable for automobile quickly driving and becomemore and more important in urban transportation system. Exit always become thebottleneck of the expressways system, so we should do is to take efficiency measureto increase the capacity of exit. At present, transportation researchers have done much research on merge areasof interurban expressways. Not any research has been done on diverge areas of urbanexpressways. The some items the paper studied will give some advices to furtherstudy on diverge areas of urban expressways. In this paper, after discussing traffic behaviors on diverge areas of urbanexpressways , Microsimulation software-VISSIM is calibrated and validated througha field survey. Then six factors on three aspects that may influence the capacity of theurban expressways exit are evaluated and corresponding improving measures arebrought. At last, this paper proposes 140 meter on deceleration lane length, the secondrecommends value is 60 meter where road space resources is serious restrict.