I got the coupon book too and it doesn't say what rides will be open, but it does mention roller coasters in the description. The coupon book is mailed to season pass holders.
I'll type what it says.
As Halloween slithered along the grounds of Busch Gardens Tampa Bay last year, it found the soil to its liking and stayed to nest deep within the park's depths. This horrible mass settled into its new home and now awaits for the right season to reveal itself and disrupt the lives of unsuspecting guests partaking in Howl-O-Scream festivities. The sounds of roller coasters piercing the moonlit sky this fall my be eclipsed by the screams of guests encountering this supreme Halloween extravaganza. Brave souls willing to cross Holw-O-Scream's boundaries meet a new kind of terror for 14 haunting nights.
September 28, 29
October 5,6,12,13,18,19,20,25,26,27,28, & 31
Off Peak: Thursdays and Sundays
Event Hours: 7:30pm - 1:00am
Member admission $14.95 plus tax ($20 off regular price)
Peak Nights: Fridays, Saturdays and Halloween Night
Event Hours 7:30pm - 2am
Member admission $16.95 plus tax ($18 off regular price)
10% savings on Fright Feast Meal, "You feed before THEY feed!"
Included with our feast is a live stage performance dinner show and guests will be allowed into the Howl-O-Scream event 30 minutes before the gates open to the general admission victims.
General admission dinner show tickets are $14.95.
Too Afraid to walk Alone? Tours of Terror.
Receive front of the line access to all 5 Haunted Houses, and live shows for $24.95.
To book reservations of for information, call 1-888-800-5447.
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Weird, the web site has employment info for the event, but not details of the event itself.
I'm driving up October 5th, I assume the roller coasters will be open, and that's the main reason I'm going, to ride them at night.