From 0cdbaa363c37c29a16e7acb3e8e133b7785405a1 Mon Sep 17 00:00:00 2001 From: Nate Wessel Date: Tue, 5 Mar 2024 14:40:05 -0500 Subject: [PATCH] Note that HERE %iles are interpolated values, not necessarily observed in sample --- here/README.md | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/here/README.md b/here/README.md index 4907ba353..4294c2a7e 100644 --- a/here/README.md +++ b/here/README.md @@ -106,8 +106,8 @@ Historical data are acquired through the Traffic Analytics download portal. Data | stddev | numeric(4,1) | | standard deviation of the observed speed(s) | | min_spd | integer | | Observed minimum speed | | max_spd | integer | | Observed maximum speed | -| pct_50 | integer | | Observed median speed | -| pct_85 | integer | | Observed 85th percentile speed - use with caution as sample sizes (of vehicles) are very small within 5-minute bins | +| pct_50 | integer | | Median speed. Likely to have been interpolated between adjacent values rather than actually observed in the sample! | +| pct_85 | integer | | 85th percentile speed - use with caution as sample sizes (of vehicles) are very small within 5-minute bins. This value may also be interpolated. | | confidence | integer | | proprietary measure derived from `stddev` and `sample_size`; higher values mean greater 'confidence' in reliability of `mean` | | sample_size | integer | | the number of probe vehicles traversing a segment within a 5-minute bin **plus** the number of 'probe samples' |