Here’s a cool piece about a University of Virginia engineering team promoting innovative ways to retool traffic signals. A key passage:
Most computer models today treat traffic flow as if it had the
relatively uniform dynamics of a stream of water ? all cars moving at
about the same rate from intersection to intersection. But [Dr. Byungkyu] Park
explains that traffic lights can be synchronized more precisely if
traffic flow is calibrated on a ?micro? rather than ?macro? level ?
that is, on the number of individual cars and trucks on the road at a
given time. That makes for a huge computational challenge, but also
opens the door to more accurate computers models that mirror real-world
traffic flows to a far greater degree.SNIP
Park?s model allows for different driving styles that impede or
change the flow of traffic. They include aggressive drivers that zoom
ahead of the pack, lane changers, and slow-rolling truckers. His goal:
to optimize light timing so erratic traffic ends up moving uniformly
?like a train.?To do that, however, would require taking special note of that bane
of traffic regulators ? the left-hand turn. Lights that hold left-hand
turn lanes at a standstill too long can lead to long backups that
impede traffic in other lanes, a common problem. His system would vary
the length of left-turn lane signals to suit traffic conditions,
allowing enough time for enough motorists to get through to prevent
backups.
I particularly like the part about rethinking the signaling of left-turn lanes. They cause significant backups in the parts of Wake County I frequent.
