Layer Estimates:

Layer: Select US Cities (10m Natural Earth) (ID:0)
Count: 7342
Extent:

XMin: -19991865.0027346
YMin: -30240971.9583861
XMax: 19968858.0135762
YMax: 17366482.8048603
Spatial Reference: 102100 (3857)

Layer: ACS Travel Time To Work Spikes (Gradient + Line) (ID:17)
Count: 3221
Extent:

XMin: -18593541.7506
YMin: 2035439.0934
XMax: -7267850.7345
YMax: 10860461.1552
Spatial Reference: 102100 (3857)

Layer: ACS Travel Time To Work (Boundaries) (ID:18)
Count: 3221
Extent:

XMin: -19942767.0256
YMin: 2023891.5042
XMax: 20012846.0377
YMax: 11528300.4769
Spatial Reference: 102100 (3857)