Give public more optionsto speak out on I-526 plan

The state Department of Transportation has proposed to complete the Mark Clark Expressway, or I-526, with a project that bears only a slight resemblance to the rest of the interstate loop. The S.C. Department of Transportation says the project's design was developed while considering last year's public comments on the proposal. But will the public support what the DOT is now proposing?

If the DOT is interested in finding the answer, it should expand its plans for public hearings to better accommodate residents on Johns Island and James Island. At present, only two hearings are planned, both at Burke High School on peninsula Charleston.

Island residents can expect major changes if the expressway, from Savannah Highway to the James Island Connector, is completed as designed. The number of planned interchanges has been increased from two to six under the latest proposal. That will mean more development associated with the extension and new traffic patterns through established neighborhoods.

The number of intersections on James Island, for example, would be increased from one to four, including a new intersection with two-lane Riverland Drive, now designated as a state scenic highway.

Although built to interstate standards of lane width and separation, the highway's speed would be limited to 35-40 mph -- about 25 mph less than the rest of the expressway. The state's broader experience with speed limit compliance on interstates raises the question whether such a sharp reduction in speed is reasonable or will be generally obeyed. Meanwhile, the eight-mile extension would alternate between an at-grade highway and an elevated roadway more typical of an interstate.

A number of questions also have been raised by traffic consultants with the Coastal Conservation League. For example, transportation engineer Richard Hall says the addition of at-grade intersections with stoplights will sharply reduce the highway's capacity to handle traffic -- one of the primary reasons for its construction. The league also contends that the new design doesn't mesh with the traffic plan for the suburban portion of Johns Island that its consultants helped design. And it says that the project will cover far more wetlands than originally expected.

Of course, the league doesn't want the extension, either as a traditional interstate loop or as the "parkway" now planned by the DOT. It would rather see the $489 million spent for other transportation improvements, including light rail serving commuters between Summerville and Charleston. Island residents, however, may take a different view.

As proposed, the extension would provide access for bicyclists and pedestrians, otherwise prohibited on the Mark Clark Expressway. Whatever shortcomings may be attributed to this project, increased cyclist and pedestrian access is likely to have public support, particularly with the positive experience of the Arthur Ravenel Jr. Bridge.

Since the overall project design is described as having been driven by public input, the DOT should give it a full public test before advancing further. It should add public hearings on both James and Johns Islands.

The DOT should retain at least one of the hearings scheduled at Burke High the week before Labor Day, since the completed project also will affect residents of the peninsula. A completed Mark Clark Expressway will sharply increase traffic flow onto the peninsula via single-lane exits at Calhoun Street and Lockwood Drive. Currently, no improvements are envisioned at that interchange, which already experiences rush-hour backups in the morning.

The design of the expressway extension is a major departure from the rest of the loop, as DOT project manager David Kinard acknowledged. "It's a lot different than anything we've proposed before," Mr. Kinard said last week, after the plan was unveiled.

The project also would have consequences for James and Johns Island that have not been contemplated or discussed by their residents.

If the public is really driving this plan, the DOT should be keen to hear what the people have to say.