| ArcGIS REST Services Directory |
| Home > services > NC_Senate_Transit_SGI (FeatureServer) | | API Reference |
This layer shows the Spending Gap Index (SGI) for North Carolina Senate Districts. The data is visualized into five breaks where a higher (red) value indicates districts where spending fails to meet need whereas a lower (blue) value indicates districts where spending exceeds need.
The SGI is an index that subtracts estimated public transit spending from the PCI score. These two metrics are normalized into z-scores before their subtraction. A district with a +1 z-score for spending and a +1 z-score for PCI would have an SGI score of 0 indicating that the district perfectly meets their transit needs. Similarly, a district with a +1 z-score for spending and a +3 z-score for PCI would have a SGI score of +2 indicating that the district is underfunded relative to public transit need.