Joaquin Road, Portola Valley map

Statistics:

Max. grade: 20%
Main climb:
Avg. grade: 14.6% (elev. gain/dist)
Length: 0.35 miles (0.56 km)
Elev. gain: 270 feet (82 m)
Entire profile:
Avg. grade: 14.5%
Length: 0.38 miles (0.61 km)
Climb: 270 feet (82 m)
Descent: 20 feet (6 m)

Description:

Joaquin Road is a short but steep road near the top of the paved section of Alpine Road (east of Skyline). It climbs about 250 feet in 1/3 of a mile. The first few meters are gentle, but most of the climbing hovers between 14% and 18%, with one short stretch hitting 20%.

Altimeter altitude

(Altitude linearly interpolated from altimeter samples, and smoothed with a 0.04mi gaussian.)

Each horizontal line is 100 feet. Each vertical line is 0.2 miles.

Gradiometer grade

(Grade linearly interpolated from gradiometer samples, and smoothed with a 0.04mi gaussian.)

Each horizontal line is 2% grade. Each vertical line is 0.2 miles.

Altimeter grade

(Grade linearly interpolated from altimeter samples, and smoothed with a 0.20mi gaussian.)

Each horizontal line is 2% grade. Each vertical line is 0.2 miles.

Comparison of grades

(Green grade is from the gradiometer, magenta grade is from the altimeter, and white is where they overlap.)

Each horizontal line is 2% grade. Each vertical line is 0.2 miles.

Overall (averaging my first 20 hills), the gradiometer grade averages 0.63 (% grade) higher than the altimeter grade, with a standard deviation of 4.5 (% grade per road). This error may be due to:

In the end, though, I think that each individual sample is accurate to within about 2% for that instantaneous segment of road. My results may not always agree with my altimeter, but they are generally repeatable within 1%. I think that I just need to take more samples to generate more accurate graphs.

Raw Data:

Dist    Grade   Alti.   Location
----    -----   ------  --------
0.00	  0%	1130	start - alpine Road
0.01	 12%	1130
0.03	 16%	1140
0.05	 15%	1160
0.07	 14%	1180	30 Joaquin - left turn
0.09	 12%	1190
0.11	 17%	1210
0.12	 17%	1220	right turn
0.13	 16%	1230
0.15	 15%	1240	50 Joaquin
0.18	 15%	1260
0.20	 16%	1280	60 Joaquin
0.22	 20%	1300	
0.23	 17%	1310
0.25	 11%	1320	75 Joaquin
0.26	 17%	1330	right turn
0.28	 16%	1340
0.30	 15%	1360
0.32	 16%	1380
0.33	 15%	1380
0.34	  9%	1390
0.36	  0%	1400
0.37	-13%	1390
0.38	  0%	1380


Back to Lucas's cycling gradiometer page.