OTP distance data appears incorrect at ZCTA scale

[ccsarapas]

For example, plotting driving times to nearest OTP at the tract level (left panel) appears to correspond to locations of OTPs, but by ZCTA (right panel) doesn't:

Looking at the data, ZCTAs with lower distances have higher drive times. Plus the count of OTPs within 30 minutes has fractional numbers, which doesn't seem to make sense.

# A tibble: 1,383 × 4
   GEOID OtpMinDis OtpTmDr OtpCntDr
   <chr>     <dbl>   <int>    <dbl>
 1 60002      9.22       4    17.4
 2 60004      4.2       10    10.9
 3 60005      4.3       13     7.51
 4 60007      8.1       14    12.3
 5 60008      1.89      12     0
 6 60010     10.5        6    20.6
 7 60012     15.0        0    30.2
 8 60013     14.4        1    28.3
 9 60014     15.3        1    26.0
10 60015      9.5       11    16.0
# ℹ 1,373 more rows

Other drive time variables (e.g., FQHCs, MOUD providers) at the ZCTA level seem correct, it's just the OTPs.