When a Data Geek Hits the Road
I’ve been offline for a while, primarily because I’ve been in the process of relocating my family from Austin, TX to Dublin, OH (Columbus, OH, basically). The last part of that relocation was me driving the entire trip in one shot with our two labs. My wife and our three kids had left two weeks earlier, taken a meandering trip up, then handled the closing on our Dublin house and the movers showing up and getting everything moved in.
Things did work out well for me there.
But, to the data geek front:
I decided that I’d go for a one-day trip, with a planned “out” to get a hotel if things got unsafe fatigue-wise. According to Google, the door-to-door trip was 1,272 milies and would take about 19 hours and 43 minutes. I brought along the driving directions, which I followed to a T, and logged actual elapsed times and mileage at various waypoints along the journey.
Miles | |||
Waypoint | Actual | % Difference | |
Depart Dripping Springs, TX | 0.0 | 0.0 | – |
Exit I-35E onto I-30 E in Dallas, TX | 215.5 | 203.0 | -5.8% |
Exit I-30 onto I-440 E in Little Rock, AR | 531.5 | 505.4 | -4.9% |
Exit I-440 onto I-40 E in Little Rock, AR | 541.5 | 515.0 | -4.9% |
Stay on I-40 E in Memphis, TN | 681.4 | 649.0 | -4.8% |
Stay on I-65 N as leaving Nashville, TN | 880.5 | 840.0 | -4.6% |
Take I-71 N in Louisville, KY | 1056.8 | 1008.0 | -4.6% |
Stay on I-71 N in Cincinnati, OH | 1128.4 | 1095.2 | -2.9% |
Arrive Dublin, OH | 1272.5 | 1215.3 | -4.5% |
Not a bad variance, actually. And, who knows? Maybe the odometer on my truck is off. The fact is, I didn’t particularly care how far I drove — the critical factor was how long I drove. So, how did Google do on the timing front? Same waypoints, but cumulative elapsed times: Google’s estimate versus the digital clock in my truck:
Cum. Hours | |||
Waypoint | Actual | % Difference | |
Depart Dripping Springs, TX | 0.0 | 0.0 | – |
Exit I-35E onto I-30 E in Dallas, TX | 3.5 | 3.1 | -9.6% |
Exit I-30 onto I-440 E in Little Rock, AR | 8.2 | 8.0 | -1.8% |
Exit I-440 onto I-40 E in Little Rock, AR | 8.3 | 8.2 | -2.0% |
Stay on I-40 E in Memphis, TN | 10.4 | 10.1 | -2.9% |
Stay on I-65 N as leaving Nashville, TN | 13.3 | 13.2 | -1.1% |
Take I-71 N in Louisville, KY | 16.1 | 15.9 | -1.4% |
Stay on I-71 N in Cincinnati, OH | 17.2 | 17.2 | 0.0% |
Arrive Dublin, OH | 19.6 | 19.5 | -0.8% |
Holy. COW! I arrived 10 minutes earlier than Google predicted after driving over 1,200 miles!
Now, to be a good data analyst, I’m going to have to assume that, if I made this same drive 100 times, I wouldn’t hit it within 10 minutes all that often. There are simply too many variables. What would the standard deviation of my total trip times be, though, I wonder? At a minimum, we’ll have to wait until gas prices come down considerably and until I slip into some sort of mild dementia to find that out. 19 hours of driving…solo…in one day was fairly brutal, and not the safest of things to do!