Workers will put the finishing touches on changes to the Sam Houston Tollway this weekend. When the tollway reopens Monday, only motorists with electronic transponders will be able to drive across the Ship Channel Bridge.

The last bit of work means the entire tollway will close between Texas 225 and Interstate 10 from 8 p.m. Friday until 5 a.m. Monday. The suggested detour for traffic in both directions is to use I-10 and Texas 225 to head east and then travel to Loop 610, then back towards the tollway.

Travelers can also use the Washburn Tunnel east of the tollway, though Harris County Toll Road Authority officials said traffic is expected to be heavy because of the tollway closure. Large, multi-axle vehicles such as 18-wheelers are banned from using the tunnel.

In a news release, HCTRA officials said the Lynchburg Ferry also will operate extended weekend hours for those crossing the Ship Channel. Ferries will operate from 9:30 a.m. until 8 p.m. Saturday and Sunday.

"We appreciate the patience off all drivers who will be affected by the weekend closure," HCTRA spokeswoman Mary Benton said.

Crews are converting the Sam Houston Tollway to all-electronic tolling to improve traffic flow and safety, toll officials said. Along with the conversion, HCTRA became the first toll agency in the country to offer a reloadable accounts connected to a transponder drivers can use in their vehicle. The reloadable accounts are targeted at users who for various reasons, such as lack of a credit card or desire not to provide banking information, do not have the conventional EZ TAG account.

More than 500 drivers have purchased a reloadable EZ TAG account, said Shannon Swank, vice-president of BancPass, the company handling the payment system for HCTRA.

HCTRA is also converting segments of the Hardy Toll Road to all electronic tolling as part of a broader widening and rebuilding project near Interstate 45 in Spring.