Looks like I'm getting the hang of pulse and glide. Luck is involved here, too - green lights, no one behind me. Was aiming for around 76 or 77 on the Prius display - you can see that toward the end whatever experimentation I did with a slightly different route was a total mpg failure :-)
I've dialed down Scangauge's peppy fuel economy optimism by about 5%, so these days it's showing the approximate true mileage. I'll happily take it for weather in the 30s!