Art Museum Loop Tempo Run

From the time I knew I was moving in early/mid April I knew my 8 mile tempo run would be around the Art Museum Loop.
Where as all my Cobbs Creek Parkway runs were "eyeballed" I knew the loop was 8.4 miles as it's marked every 1/4 mile.
My splits went:
6.26
13.04
19.48
26.52
40.11
47.32
53.10
57.13
I'd like to get that down to sub 57 next week and then continue to lower my splits over the coming weeks and months.