文档介绍：CIRCULAR LOGIC
Contents
1. Introduction 1
2. Assumptions 2
3. Axiomatic Traffic Theory 2
. Introduction 2
. Axioms 4
. Derivation of Entrances and Exits 6
. Algorithm 11
4. Traffic Modeling in a Traffic Circle 15
. Algorithm Description 16
References 22
CONTROL NUMBER: 4095
1. Introduction
Traffic circles or roundabouts have been in use in Europe and other places around
the world where they often replaced old public squares with the introduction of
the car. Given the irregular nature of some of these old public spaces and and the
streets that entered them, allowing motorist in the circle to proceed unimpeded
while requiring motorist entering the circle to yield may have seemed like the
only way to deal with the situation. Over time, roundabouts have been built as
flexible, efficient intersections, often where the ing road approach irregularly,
or where their traffic volume are asymmetrical [6]. More recently, in the United
States. traffic circles have been monly utilized as efficient replacement
for controlled intersections, indeed their use has been growing exponentially there
[5].
Despite their advantages, there are problems. Motorists in the United State
are largely unfamiliar with them and either misuse them or are unnecessarily
cautious. The most recent large Transportation Research Board study of traffic
circles [5] found evidence that clear lane markings and inclusion of additional entry
lanes improved traffic circle safety and performance. Moreover, they found that in
multi-lane traffic circle those with the highest crash frequencies were those with
lane overlaps in either entry or exiting. Given this, one must be fairly sophisticated
Date: 02/09/09 (In Theory).
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2 CIRCULAR LOGIC
about what one means by controlling ’right of way’ when es to traffic circles;
that is, simply postulating that entering vehicles must yield to those already in the
circle (or visa versa), is not very helpful since what matters is the arr