State Wide Model
Access Scores No Max Impedance
Brian Froeb
5/19/2021
Initial Summary
For the sake of this analysis the TAZ representing Puerto Rico as been dropped as it was a significant outlier arising from zero minute travel times. The leaves 9775 TAZs in the analysis.
Overall the data is positively skewed, with a skewness of 0.6641634. The data is also platykurtic, meaning there are fewer and less extreme outliers than in a Normal distribution, with a kurtosis of 2.2609266. The full set of descriptive statistics are below, the higher mean than median further indicates the positive skew of the data.
Summary Statistics
| Minimum | 25th Pct. | Median | Mean | 75th Pct. | Maximum | Std. Dev. |
|---|---|---|---|---|---|---|
| 0 | 174133.2 | 466724.4 | 610124.4 | 977981.3 | 1803577 | 509664.2 |
The full distribution is shown in the following histogram. 
Florida only
The TAZs included in the Statewide model cover the entire US and parts of Canada and Mexico, for ease of mapping the rest of this analysis will focuses exclusively on the 8996 TAZs within Florida.
Overall the pattern is similar, but with a significant number of low values removed raising the minimum value to 12234.1437669. The data is still positively skewed, skewness: 0.6101286, and platykurtic, kurtosis: 2.1849065.
Summary Statistics
| Minimum | 25th Pct. | Median | Mean | 75th Pct. | Maximum | Std. Dev. |
|---|---|---|---|---|---|---|
| 12234.14 | 227628.8 | 527353.9 | 662105.8 | 1023171 | 1803577 | 509664.2 |
The distibution of Florida TAZs is below. 
The peaks in the distribution appear to correlate with specific geographic distributions. The peak between 1.25 and 2 million corresponds with Miami, the peak between 0.7 million and 1.25 corresponds with the outer ring of Miami and the central areas of Orlando and Tampa, the peak between 0.3 and 0.7 million corresponds with the outer ring of Orlando and Tampa, the eastern coast of from Jacksonville to Orlando, and the coast south of Tampa.
Access scores as well as the geographic regions are shown in the maps below. The access score map also represents the employment density of a TAZ by extruding the TAZ, taller TAZs have higher employment density. The region map has the TAZs extruded by their access score. The maps can be panned with a left click and tilted with right click.