Video detection of bicycles for traffic lights

Most cyclists have encountered stubborn traffic lights that don’t detect bicycles or motorcycles. Since 2009 in California, new traffic lights that detect traffic must also detect bicycles and motorcycles. This law requiring bicycle detection for actuated traffic lights has encouraged some additional innovation by traffic equipment vendors.

To comply with state law while maintaining a high level of vehicle throughput at busy intersections, the city of Pleasonton, CA experimented with a radar device that can differentiate between bicycles and automobiles, and provides longer green light times for bikes to allow them to safely cross large intersections. The city now has several intersections with the bicycle differentiating technology provided by their vendor MS SEDCO.

Another traffic equipment company, Interis Iteris, announced their SmartCycle bicycle detection for video traffic signal controls. Their SmartCycle uses existing Iteris video detectors and other hardware to differentiate between bikes and cars and offer longer green light time for bicycles. Says their marketing material:

Cyclists are becoming more prevalent across the country and extra phase time is needed to allow them to safely exit the intersection on. When no bicyclists are present the additional cycle time is wasted reducing efficiency of the traffic network. Reclaiming this unused time can greatly improve traffic flow while ensuring the safety of the cycling public.

According to Iteris, this additional capability is a simple firmware upgrade for existing equipment that can be used for their entire Vantage detection family of video detection processor products, including: Edge2, SmartSpan, Vector, and VersiCam. Iteris is offering this firmware upgrade to their existing users at no cost.

Iteris points out California’s requirement for bicycle detection for traffic lights that are actuated by traffic. AB 1581 became effective in 2009; this law requires that when traffic-actuated signals are first installed or are replaced that they must be capable of detecting bicycles and motorcycles as well as motor vehicles. I love this part of their FAQ which answers the question “Why should I care about this outside of California?”

Bicyclists do legally operate on roadways in your jurisdiction. Their acceleration from a stopped position, as well as their design speed, is much slower than the rest of the traffic stream. In order for bicycles to be safely accommodated at signalized intersections (an undeniable goal), the phase timing must be adjusted upward to provide for these slower vehicle characteristics. In particular, the minimum green time and the final passage time must both be set to be longer than they would be for a traffic stream that is composed only of ‘regular’ motor vehicles. If the detection presence of bicycles is non-existent at a traffic signal, the only way that their safety can be provided for is for their presence to be assumed on every signal cycle. This would lead to more sluggish timing of the traffic signal, and create a significant amount of extra delay to the rest of the traffic stream. Detecting bicycles accurately, and only providing the extra time when they are present, keeps the traffic signal operating at improved efficiency and throughput. So, detecting bicycles achieves a dual goal – to accommodate this slower class of lawful vehicles with appropriate safety, and to keep traffic signals operating as efficiently as possible in the absence of bicycles. Either goal by itself is sufficient reason for all actuated signals – nationwide, not just in California – to be equipped with robust detection of bicycles.

Read more about Iteris SmartCycle here. I’m happy to see companies like Iteris and MS SEDCO creating traffic control technology with bikes in mind.

Thanksgiving Weekend Carnage

The California Highway Patrol reports 21 fatal traffic collisions over the Thanksgiving holiday weekend.

Continue reading Thanksgiving Weekend Carnage

Rave On

My son attends Texas Tech University in Lubbock, Tex and has finally given up on keeping his old Dodge RAM pickup running. For many months now I have been gently guiding him toward the bicycle as a form of transportation in a town not known for elevation changes.

Of the three bikes hanging in the garage, I gave him the choice of the three. He is built to be a road cyclist with the metabolism of a hummingbird and the lithe frame of an endurance athlete, and while he did choose my favorite road bike, he is not yet comfortable with drop bars.

This morning’s task was moving parts around all three bikes to make him one helluva lean flat bar road bike. Unlike other ‘hybrids’, this one truly is a road bike, with the geometry and road calipers vs. V-brakes (my preference). I don’t know why I didn’t do this before. The good news is that not only will he be saving a load of cash and staying healthier, but the 9 speed group that was on this bike are now on my other bike. No need to go buy stuff!

Wait, it gets better.

My LBS is a mail-order/online house mostly, but has a small showroom with the best peeps on the local scene. As it turns out, while down there picking up the FD for the bike build, the guy who helped me spent four years at TTU and grew up in southeastern New Mexico, making Lubbock a larger city nearby. I am not concerned with my son’s ability to ride a bike, but I am interested in the commuting climate, security on campus, and the bike shops in the area.

He knows the shop owners, the clubs, and the environment. Talk about a sign. I’ll be driving the bike down to Buddy Holly’s hometown in a few weeks and will take an extra bike for a ride down there myself. Lots of pictures to come and hopefully continuing good news of bicycle adventures in north Texas.

DUI and riding at night

Colorado Springs ranks consistently high in the Men’s Health survey (the only national survey I am aware of, and Colorado Springs is 16th for 2010) of drunkest cities in the U.S., so it follows that DUI is a big problem here.

This past weekend, a cyclist was struck and killed by a hit and run driver at 1:00 a.m. while coming home from work. Having commuted at night for a couple of years, it goes without saying that vigilance is paramount in this arena. As cyclists, one of the first things we think when we read these reports are: Was drinking a factor, and was the cyclist reflective and well-lit? All that is clear in this case is that drinking may have been involved. Continue reading DUI and riding at night


Half of my commuting trips involve a MUP of some sort, and I have been noticing a theme of sorts with the people I encounter on the path. It is a wide, paved network of trails that run along Interstate 25 (North-South) and to Garden of the Gods to the West, but not so close you see or hear traffic. There are runners, dog walkers, baby strollers and a large warren of rabbits, who have caused me much grief over the years.

Continue reading Pleasantville

Here’s Your Sign

There are several routes available to and from work on my daily ride, and it has come to my attention that more and more (not like dandelions in Spring) Share The Road signs are going up, appropriately in areas where there is a wider lane, but no designated bike lane.

I do not believe this changes the behavior of most motorists, it merely gives us something to point to in case we are involved in a collision with a car. Ride like you belong on the road, and use care when taking more of the lane than you should (potholes, roadkill, hazards of any sort). Blinkies on your backpack or messenger bag also help.

Does anyone anywhere else see positive improvements to their commuting/riding experience?