Crash barriers line Main Street between Bonneville and Carson avenues this week. More than 3,000 barriers -- weighing more than four tons each -- are being placed along downtown Las Vegas streets that will be converted into a temporary race course for the Vegas Grand Prix on April 6-8. Photo by Gary Thompson.

This week, readers want to know why downtown Las Vegas streets are getting fenced in and why a road far from the city is getting worked on.

And the Road Warrior wonders if the jets overhead can affect the hearing of a driver down in the valley.

Larry asks: Just curious what those strange fences are that are going up in downtown Las Vegas. It almost looks like a concentration camp.

Don't worry, Larry. Downtown isn't getting walled off and converted into some sort of down-and-out penal colony, a la "Escape From New York." Rather, the barricades are for a kind of live-action episode of "Speed Racer."

The barricades are outlining a temporary 2.4-mile course for the inaugural Vegas Grand Prix, a Champ Car auto racing league event scheduled for April 6-8.

In place by race day will be around 3,000 concrete barriers, each of which is 12 feet long, more than 3 feet high and weighs 4 1/2 tons. The barriers are topped by a 9-foot-tall metal screen to protect onlookers from debris, and all the barriers will be linked together, according to race organizers.

Organizers are also setting up 800 tire barriers, each of which consists of 25 bundled and interlocked tires, organizers said.

Streets lined with barriers include Main Street between Bonneville Avenue and Carson Avenue; Grand Central Parkway from Ogden Avenue and Bonneville; Bonneville from Grand Central to Main; Carson from Main to First Street and from Casino Center Boulevard to Fourth Street; First and Casino Center between Carson and Bridger Avenue; Bridger between First and Casino Center; Fourth from Carson to Ogden; and Ogden from Fourth to Grand Central.

Starting April 4, drivers can expect a series of downtown street closures. And temporary changes to Citizens Area Transit routes 105, 106, 108, 207 and "The Deuce" can also be anticipated.

Major downtown byways that will remain open and are suggested as detours include Interstate 15, U.S. Highway 95, Las Vegas Boulevard, Charleston Boulevard, Stewart Avenue, Bonanza Road and Washington Avenue.

More information on the race is available by calling 944-8661 or online at www.vegasgrandprix.com. Traffic access information can be found on the city's Web site at www.lasvegasnevada.gov. And information on bus service is available online at www.rtcsnv.com.

Steve Rose asks: I live in Pahrump and wanted to know what is going on with all the road construction on state Route 160 between Mountain Springs and Pahrump.

Those who take that narrow road know about the lack of shoulders, something that's given drivers little to no margin of error when commuting to and from Las Vegas. The work is aimed at lessening that problem.

Engineers are widening some highway shoulders along a 22-mile section of road around the Mountain Springs summit as part of a $23 million project that began in September 2006, according to the Nevada Department of Transportation.

Workers also are adding roadway "buttons" and grooved roadside "rumble strips" to help alert drivers when they might be drifting out of their lane of travel, NDOT said.

"It's mostly a safety project," said Mary Martini, NDOT's district engineer for Southern Nevada. "What it didn't have before were adequate shoulders."

Most of the widened shoulders are on the inside of the road, not outside. Martini said right-of-way issues hindered the ability to increase the outside shoulders, which abut U.S. Bureau of Land Management property.

The project is expected to wrap up in November.

Later, NDOT plans to add so-called "dynamic message" signs along Route 160 on either end of the pass. The electronic message boards will provide drivers with real-time updates about upcoming road conditions, something engineers see as a user-friendly tool allowing drivers to learn of and avoid bad weather or wrecks at the summit.

"It will allow us to put out messages to the public, especially if there's a weather event on the summit," Martini said.

Engineers hope to have those signs in place no later than the end of next year, according to Martini.

Hit 'n Run: Seen recently on the Nevada vanity plate of an SUV on Main Street at Fremont Street: "2DEF4U." Too deaf for you.

HUH??? WHADDYA SAY????

I CAN'T HEAR YOU WITH ALL THESE JETS TURNING OVER TOWN!!!!

If you have a question, tip or tirade, call the Road Warrior at 387-2904, or e-mail him at roadwarrior@reviewjournal.com or OSofradzija@reviewjournal.com. Please include your phone number.