One of the things that really lowers my average speed on my commutes is the fact that i have A LOT of 4-way stop and traffic light intersections on my urban street commuting route. because intersections are where most of the dangerous interactions between cars/bikes/pedestrians occur, having an intersection-heavy route can be a hindrance to maintaining a high rate of speed, unless you're on the more reckless end of the riding spectrum and disregard traffic laws altogether. on the plus side, all of that slowing down and restarting is a good workout.

i thought it would be interesting to compare how "intersectiony" my regular commuting route is to others. so here's how it works, add up all of the controlled intersections you encounter on your regular bike commute route and then divide by the total miles. for definition purposes, let's call a controlled intersection any point where 2 or more roads, streets, MUPs, etc. come together where right of way is controlled in your direction of travel by a stop sign, traffic light, roundabout, or some other such device. don't include intersections where you have 100% right of way 100% of the time. although those can certainly be dangerous too (perhaps even more so in some circumstances), this exercise is focused on intersections where you encounter a controlling device in your direction of travel.


for me: 45 controlled intersections / 5 mile route = 9 IPM's (Intersections Per Mile)


so, what's your IPM number?



disclaimer: if you don't have a regularish commute route and take a different route to your place of employment every single morning, then this thread isn't for you.

I guess my intersections per mile is just under 3 on a seven mile commute (20 intersections.) Only two controlled by traffic signals in the morning (there are two others, but they are flashing yellow during my commute time.) One traffic circle. 7 crosswalks. 3 stop signs. The rest are uncontrolled intersections and rarely require a stop.

My Greenway route: IPM is .65
Regular roads: IPM is 2.3

Which is a big part of why I default to the Greenway. Waiting on lights on average (including the times I hit it green) costs me I guess five or six minutes.

While I use all sort of routes and variations, the vast majority of my commutes slot into one of three routes going to work, and two coming home.

Going to work
26 stops, 4.5 miles, 5.7 stops per mile: Direct route, par time 20 minutes
23 stops, 9.3 miles, 2.5 stops per mile: Hills, parks, cemetery and trails route, par time 35 minutes
20 stops, 16.3 miles, 1.2 stops per mile: Long loop (Pittsford), par time 60 minutes (9 miles non-stop on the MUP)

Coming home
27 stops, 4.6 miles, 5.8 stops per mile: Direct route, par time 20 minutes
17 stops, 13.3 miles, 1.3 stops per mile: Brooks Landing cut to long loop (Clover St), par time 50 minutes, (6 miles non-stop on the MUP)

If anything, I've missed a few stops riding the routes in my head today.

You can see why I use the direct route only in foul weather. OTOH, when riding it regularly in the winter, what I lose in endurance I gain in awesome sprinting legs.

Plus, the number of stops in my commutes means that starting from a stop, I can clip-in two to three times faster than anyone else in my club. I'm clipped-in and gone while they're still wobbling around in the intersection looking at their feet.

Of course, my brake pad budget is pretty high.

Interesting post.

I have 14 in 3.5 miles, so only 4 IPMs; not too bad...

Man, it really depends how I count. There are a couple places I ride past unmanned guard shacks and a couple places on MUPs where no one obeys stop signs.

My route home today is going to be 14.2 miles with 51 such intersections. So that's 3.6 IPM.

Im glad for my route. I ride 15miles one way with 15 intersections. But 13 of the intersections are all in the first 2 miles. The last 2 intersections are when the MUP crosses the main road somewhere in the middle of the route. Pretty peaceful ride and almost perfectly flat to boot.
So technically 1 IPM.

My way home is never really the same way, so I can't calculate that.

Short way: 4 IPM
Long way: ~10-12 IPM

To work 2.2
going home 1.9

Looking over some of the numbers here I guess I have it easy.

Boy do I have it good.

Inbound: 7/12 = 0.58
Outbound 5/12 = 0.42

With this commute, I can keep it moving pretty good and I guess I shouldn't complain when I get stopped.

I count 10 stopsigns or stoplights on my 5.5mi route, so IPM 1.8.

I think that's actually forgetting a couple other lights that are green like 99% of the time (like one for a school that is only active when kids are coming in&out, one for a park/firehouse)

Great question for me and one big reason I think I have the luckiest commute route.

NYC is notorious for insane traffic. If you haven't been to NYC, you have no idea. On north-south avenues, there are TWENTY intersections per mile. But I don't have to ride on the streets for most of my commute. I ride a bike path which has virtually no intersections, and that path is most of my 13-mile commute. I just counted on the map. There are about 30 intersections on my route, so that's 2.3 intersections per mile. When I first started taking this path, I was astonished at how fast I got to my destinations. I got there early!

thanks for the responses all. as i suspected, my IPM of 9.0 appears to be on the very high side. oh well, not much i can do about it unless i take a different job located somewhere else and move to a different place.



your long way has an IPM 3x greater than your short way?

that seems counter-intuitive.

Well my short way is 1 miles and I hit 4 intersection in that time.

My long way is about 3 miles, yes the long way is not ideal. Sometimes I run an errand before work or after and the long way is what I usually have to take to get the errands done. The short way is if its just home to work or work to home.

^ gotcha.

i was mistakenly assuming that your long way would have incorporated some kind of off-street trail or MUP that would have most likely lowered your IPM.

i can take a slightly longer route that takes advantage of an MUP, but getting to/from the MUP is still loaded with intersections, in total it's 44 controlled intersections over 8 miles for an IPM of 5.5. that's better than the 9.0 IPM of my regular route, but 44 controlled intersections is still roughly the same total number. that's just life in the big city, i suppose.

I haven't counted the intersections for roads, but my old route to work had 8 railroad crossings in a 5 mile commute. I was a pro at waiting for trains then.

3/4 . 60% of my commute is off road. 30 mi RT.

I'm in NYC and have 35 intersections over 5.5 miles. That's only 6.4 "IPM", which is pretty good for NYC. It reflects the fact that a big chunk of my ride is over the Manhattan Bridge and along the East River bike path where there are no intersections to speak of. There are pedestrians to deal with there, however.

26-mile, one-way commute. I lost count of intersection control devices at around 60. My brain is tired now.

17 traffic lights and 7 roundabouts in 11.6 miles

https://www.bikeforums.net/commuting/...l#post18118817

NYC - 126 lights in 7.5 miles. The west side greenway adds 1.5 miles to the commute and it is not practical to go as fast on much of it. See the mup thread as well - https://www.bikeforums.net/general-cy...-all-mups.html

Current most favored route:

In to work: 3 stop signs and 4 lights in 12 miles. .583 IPM

Coming home: 6 stop signs and 4 lights. .917 IPM

My other routes have similar IPM's.

There have been a few times where I caught all the lights green and safely rolled the signs and never stopped once.

I also have 4 rail crossings, but don't get stopped by a train often.

12 lights or potential stop in 41 miles round trip. I don't count stop signs I can roll through. If I ride in the shoulder and encounter a stop sign it's always clear for a right turn. 0.3 stops/mile.

Suburban side of train: 2.66 ipm: 11 stop signs and 5 stop lights over 6 miles. There are many more which are either uncontrolled or controlled only for cross traffic. I rarely have to stop at any but 2 of the signs and 3 of the lights, so in practice ipm is 0.83.

Downtown side of train: 14 ipm: 14 lights over 1 mile. They are timed so I usually have to stop for 5 of them. Practical ipm is 5.