Design Con 2015

The connected car and congested traffic

-August 20, 2014

Recently there has been a great deal of hype about how connected cars will revolutionize driving and improve safety and comfort for all. While I agree that some of these technologies will provide positive benefits, they are not going to address and solve some fundamental highway and roadway issues.

Recently I took a road trip from the SF Bay Area to San Diego. The drive was fine and would have been able to utilize adaptive cruise control, lane change warnings, streaming media to the vehicle, live traffic updates, and real-time GPS. Unfortunately there was a hiccup in the flow, and - consequently - the advantages these technologies bring.

There was a single-vehicle car fire that started a small fire on the side of the road and hills. The result was the five-lane freeway was down to one lane. Needless to say, the traffic went from 75 mph in five lanes to one lane at five to ten miles per hour and resting at a dead stop. The traffic also "closed up" to minimum distance between cars on the order of inches versus feet. In this mode the object warning systems kind of shut down, as they would be in constant warning mode with objects being too close.

In this stalled condition on the roads - a number of these kinds of events happened. First there was interruption in the smooth streaming of data and content due to the network congestion on the single cell tower. This interrupted the music being played, sending and receiving route option information, sending and receiving SMS messages, surfing the web, and even getting phone lines out. For connected vehicles that rely on the connectivity for operation and reporting, such as an autonomous vehicle might, this can be an issue.

A recent road trip from the SF Bay Area to San Diego demonstrated how new automotive technologies can be tripped up by a simple traffic hiccup.

In this scenario, the traffic mess was aggravated by a couple of minor fender benders in the close traffic due to merging. As these took place at below 10 mph and in very close quarters, it is doubtful that a collision avoidance system and lane change warning system would have prevented these events. The condition was such the driver would most likely override the automatic system in favor of "doing it himself" as it would seem a manageable task.

The reality is these situations do not have traffic control and direction in place for the lane merge, and there are no formal algorithmic rules for how the merge should work, just de facto methods. As a result this makes this complicated to automate. Vehicle to Vehicle (V2V) communication may help in this situation, but it still has to have the warnings observed by the drivers.

The second complication to the mess was the stoppage of operation of several all-electric vehicles in the course of a two-hour traffic delay. While planned with a charge to make their standard sub 50-mile run, the one-hour-plus of creeping in below 10-mph traffic did not allow the systems to regenerate any power from motion, and they burned a lot of power conditioning the cabin in the 100°F+ temperatures for the occupants.

In this small traffic mess there were at least four all-electric vehicles (multiple makes and models) that were being pushed to the side of the road, in the middle of the congested cars, to allow traffic to try and move past. A CHP officer said that they are a problem as they can really only be towed away after all the traffic returns to normal, as there is no "quick fix" - such as a gallon of gas - to get them going. The expectation was about a four to six-hour for those drivers.

While the car fire and multi-lane closure was not an everyday experience, the delay put us in the standard 10 to 15-mph multi-lane parking lot known as Hwy 405 at 4:30 PM on a weekday. This is six lanes of packed cars and trucks that occur about six days a week, even with a 24-hour commuter lane.

For autonomous cars to take hold and be responsible vehicles, their use in high-density traffic situations that exist near every major city in the world needs to be evaluated, along with residential and in-city conditions. The re-education of the driver to be able to use these vehicles in these conditions is going to be a big part of their introduction to the mainstream.

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