**The Math of Speed!**
**Faster is Safer! **

First, let me qualify;

1. My riding is in an urban area and 95% of the streets-roads are 30 mph limit.

2. I ride on the right side of the road, going "with traffic", as is the legal method.

For ease of math - Let's figure a 10 mile trip, w/traffic @ 10 cars per minute.

**30 mph traffic:**

At 10 mph -

60min x 10cars - 1/3 (for 1/3 speed of cars) = 400 cars passing you at 20mph.

At 15 mph -

40min x 10cars - 1/2 (for 1/2 speed of cars) = 200 cars passing you at 15mph.

At 20 mph -

30min x 10cars - 2/3 (for 2/3 speed of cars) = 100 cars passing you at 10mph.

AND, cars have twice the time to notice, and avoid, you! (vs 10 mph).

At 25 mph -

24min x 10 cars -5/6 (for 5/6 speed of cars) = 40 cars passing you at 5mph.

At 30 mph -

20min x 10cars - 3/3 (for 3/3 speed of cars) = 0 cars passing you!

(Math is simplified - but "sound")

When you consider that many bike accidents are directly related to passing cars, then 20 mph would be (4 times safer than 10 mph) x (2 - twice the time the, approaching, driver has to see biker) = **8 times safer @ 20 mph**, compared to 10 mph!

**Most impressive is that each speed increase of 5 mph reduces the volume of passing traffic by, an additional, 50%! **

A__hole factor! Everyone might agree that, possibly, 1 in 100 motorists are AHs toward bicyclists, (Conservative Estimate!), Going 10 mph you'll get passed by 4, only 1 @ 20 mph and at 30 mph you might never encounter 1.

**Faster is Safer! **

I've demonstrated how faster is safer, in a 30 mph traffic environment. But "On the road", with higher speed traffic, is where the most concern about passing vehicles exists. How does speed effect your risk in a 60 mph traffic situation.

First, let me qualify;

1. Riding is in an rural area and 95% of the roads are 55 mph limit.

2. I ride on the right side of the road, going "with traffic", as is the legal method.

For ease of math - Let's figure a 10 mile trip, w/traffic @ 10 cars per minute.

**60 mph traffic:**

At 10 mph -

60min x 10cars - 1/6 (for 1/6 speed of cars) = 500 cars passing you at 50mph.

Driver has 7 seconds to notice & accommodate biker.

At 15 mph -

40min x 10cars - 1/4 (for 1/4 speed of cars) = 300 cars passing you at 45mph.

At 20 mph -

30min x 10cars - 1/3 (for 1/3 speed of cars) = 200 cars passing you at 40mph.

Driver has 9.5 seconds to notice & accommodate biker. Cars have approx. 1.4 times the time to notice, and avoid, you! (vs 10 mph).

At 25 mph -

24min x 10 cars - 5/12 (for 5/12 speed of cars) = 140 cars passing you at 35mph.

At 30 mph -

20min x 10cars - 1/2 (for 1/2 speed of cars) = 100 cars passing you at 30 mph!

Driver has 12 seconds to notice & accommodate biker.

(Math is simplified - but "sound")

When you consider that, in "open road" conditions, most bike collisions are directly related to passing cars, then 20 mph would be (2.5 times safer than 10 mph) x (1.4, the time the, approaching, driver has to see biker) =** nearly 4 times safer @ 20 mph**, compared to 10 mph!

30 mph would be (5 times safer than 10 mph) x (2, the time the, approaching, driver has to see biker) = **10 times safer @ 30 mph**, compared to 10 mph!

**Note: Still "in progress" on the math, fairly accurate but will correct.**

Most impressive is that every bit of speed increase greatly reduces the volume of passing traffic and therefore increases the safety factor!

A__hole factor! Everyone might agree that, possibly, 1 in 100 motorists are AHs toward bicyclists, (Conservative Estimate!), Going 10 mph you'll get passed by 5, only 1 @ 30 mph.

"The Math of Speed" demonstrates the reduction of risk, from the application of higher speed, in many situations.

For me, faster is much safer, most of my "traffic" riding is on arterial bypasses, around the outskirts of the city, (very few driveways, side streets etc.)

"In city" I ride legally (reducing my risk of accident 50%, from the statistics) and make sure that I am seen, (the major contributing factor in all other bike-vehicle encounters.) I have tail-turn-brake light with strobe headlight and helmet with additional rear red flashy light and strobe headlight. Being able to direct a strobe light at a menacing vehicle is a real attention getter.

Having reduced the probability of all other vehicular encounters I rely on speed to help alleviate the danger of the, now, greatest danger, passing vehicles. A 90% reduction in danger, simply by increasing speed from 10 mph, to 20 mph is well worth the effort, in my book!

However, to assume that higher speed is, always, safer, is foolish, and not what I proposed. For example, residential areas might be "chock full" of driveways, or infested with playing children, or bikers etc., possibly, entering the roadway from between parked cars.

Sadly, no one has attacked the factor where speed is a true detriment, the ability to stop. ... ??? Personally, I keep my bikes, (brakes), tuned and capable of going from 20 mph to zero in, not much more than 1 car length, it takes about 5 car lengths to get up to near 20 mph. I, personally, would much rather have the maneuvering-escape speed at my disposal, and be able to lose it, when necessary.

Please vote for your "Optimum bike speed in 30 mph traffic"

**EZip Engineering 101**