Monday, April 1

Advanced Route Planning for Cyclists

On my Long Commute Home I had to choose my route carefully.  I wanted the most direct, yet most remote route I could get.  I used KYTC’s trip count maps, my handy Kentucky Atlas & Gazetteer, and MapMyRide to come up with three different options.  The first option was the one I intended to use. Then I looked at some shortcuts to shave off time if need be.  Then I let MMR auto-map the shortest possible route.

My initial criteria was low ADT (Average Daily Trips) across a direct swath west to east from Fayette County, through Clark and into Powell just north of the Kentucky and Red Rivers.  There would be lots of short steep climbs and the road would meander.  In southwestern Clark County there is no direct route along the river and you have to wind north almost into Winchester before turning back south toward the river.
A straight line from the office to Clay City is 30 miles. My initial (carefully planned) route is a meandering 57 mile trip that deviates 4 miles off the aerial path of the proverbial crow.  It’s almost twice as long.  But it also sticks to roads that have an ADT of 700 or less.  I knew before I even looked at alternate routes that any other route was going to involve roads with significantly higher ADTs.
My first alternate was basically the same general route with some straightened curves on busier roads to knock off some time, distance and elevation.  The alternate only deviates off the straight line by 3 miles and was 45 miles instead of 57.  It put me on at least one significantly busier road with ADTs of 3,449 to 1,053 to 918 (this means the road has less traffic the further you get from the city).  While the ADT decreases to more comfortable cycling traffic, it also takes ten full miles to do so.
To put things in perspective let me take you through a little mathematical exercise.  RELAX!  I’ll give you a prize if you read the rest of the post!
3,449 ADT breaks down to 143 cars per hour over the course of a single diurnal anomaly.  That’s 287 cars in a 12 hour period.  For the sake of argument (stop arguing with me!) let’s use the 12 hour figure (and knowing that there is traffic outside that time, but that it’s typically concentrated in the daylight hours).  That’s 23 cars per hour, or 2.6 cars per minute.  That’s not a bad frequency when riding a bike.  That’s moderately-light traffic.  Of course we know the cars come in clusters and it’s the clusters that kill a mood fast.
Just for kicks I let MMR auto-map the most direct route from my office in Lexington to Clay City.  38 miles.  It utilized US 60 and KY 15 and cuts directly through downtown Winchester.  First off, I didn’t even bother to look at the ADTs for the route through Winchester.  I assume congestion in any decent sized city without adequate cycling infrastructure to be stressful. 
Let’s first look at US 60.  It parallels I-64 very closely, and is the busiest road between Lexington and Winchester except for I-64.  The ADT is over 14,000 just east of Lexington and doesn’t drop below 8,000 all the way into Winchester.
Doing the same earlier math exercise at one count station along the 10 mile section of US 60 I came up with 723 cars per hour for a 12 hour period, which is 12 cars per minute, or 1 car every five seconds.  That’s a pretty continuous flow of traffic.  Even if you went back to the 24 hour period that’s still 1 car every ten seconds ALL DAY LONG.
KY 15 has lower ADT, but it’s still over 2,000 on the Clark County side and doesn’t drop below 1,000 on the Powell County side. 1,000 ADT is 41 cars per hour (24) or 83 (12).  That’s around a car a minute average.  That’s not too bad, but it’s only in the last ten miles that the frequency falls off to that level.  So the auto-mapped route goes from 14,000 ADT to 8,000 and then through the city to 2,400 to 1,000.
You can slightly alter the shortest route, keeping the distance the same, by moving south onto Todds Road which turns into Colby Road in Clark County.  It still has an ADT of 10,000 to 3,100 to 2,800 before reaching Winchester.  It would be a better route the US 60, but busier than most roads I’d be comfortable riding on.
There is another factor to consider regarding these three route possibilities: elevation.  For the meandering 57 mile peaceful route there is a total of 1,876 feet of climbing.  For the next best alternate at 45 miles there is 1,345 feet of climbing, and for the shortest (but busiest) route there is only 564 feet of gain in 38 miles.
This is unique to the geography in this part of the country, but I am certain that the major roads have been laid out away from the rugged terrain along the Kentucky River intentionally.
Here is a Google Map showing terrain and the general routes I’ve described:

Blue: Longest route with least traffic and most climbing
Yellow: Shortcuts to reduce distance and climbing
Red: Most direct with most traffic and least climbing

The last consideration to consider is timing, and this one is in some ways the hardest to quantify, but intuitively (or at least with some familiarity) you can predict the best timing fairly easily.  If your route takes you past a school then the worst times of day to ride past are the morning and afternoon rushes. Except…during the summer months. 
To maximize the benefit of timing I like to get out and ride early to beat most vehicular traffic.  The other day when I left Lexington I headed out just before noon to get beyond the city borders before lunch traffic ramped up.  Timing also comes into play with roads with high ADT.  If you’re only going to travel a few hundred yards on a road with 14,000 ADT then you’re only going to experience it for a few seconds, but if you’re going to travel for 20 miles along a heavily travelled corridor then the probability that you’ll have a close call or collision with a vehicle drastically increases.  

When I first started thinking along these lines I believed posted speed limits would play a bigger role, but I think frequency and the physical attributes of the roads actually are more important.  One thing I didn't address in this discussion was the presence of shoulders.  I think a road with 10,000 ADT and 10 foot shoulders would be fine for getting you where you need to go.  The same road with 2 foot shoulders would be a nightmare to ride. 

The other thing about posted speeds is that regardless of the number on the sign (or the spray painted number on the sign) motorists will travel at the speeds that the road is built for.  You can build a 4 lane divided boulevard with 12 foot lanes and 10 foot shoulders, but don't expect people to abide by a 35 mph speed limit.  It won't happen.

What I’ve proved (no, really!) is that the numbers once again support intuition.  Without going through this little experiment I knew from first-hand experience where I needed to look to plan my route. I knew which roads were bad for cycling and which ones might just be good. But if you were going into an unknown area and needed to plan a bike route, if you could come up with a good mapping tool that showed ADT and show elevation, you could then plan a route that would be the best balance between speed and comfort.
MapMyRide is a pretty good tool for planning routes by itself, but having those traffic counts makes all the difference in the world.
And remember, it only takes an ADT of 1 to ruin your day.  Be vigilant, be visible, and be consistent.

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