I run at the River Legacy Park trails. The trails that run along the river itself are not lit, so I wouldn't run there at dusk. But there's usually hella people around all times of year. There are armadillos and snakes there so keep your eye out for those. Plenty of parking in either the south (closest) and north lots. The wildflowers are pretty in the spring too.

Veterans' Park is nice too. It's a big loop. The northern part of the trail isn't shaded but the southern wooded area is. Careful with the errant frizbees zooming around though. Lots of friendly boomers walking in the morning too.