The Big Rock Interchange is the

I-430 Interstate 430 (I-430) is a Interstate Highway System, Interstate highway in Pulaski County, Arkansas, Pulaski County, Arkansas, that bypasses the cities of Little Rock, Arkansas, Little Rock and North Little Rock, Arkansas, North Little R ...

/ I-630/Chenal Parkway

interchange Interchange may refer to: Transport * Interchange (road), a collection of ramps, exits, and entrances between two or more highways * Interchange (freight rail), the transfer of freight cars between railroad companies * Interchange station, a rai ...

in west

Little Rock, Arkansas Little Rock is the List of capitals in the United States, capital and List of municipalities in Arkansas, most populous city of the U.S. state of Arkansas. The city's population was 202,591 as of the 2020 census. The six-county Central Arkan ...

. The name is derived from a large rock formation discovered during expansion. The interchange was originally constructed in 1977, then in the mid-2000s it was decided to expand the interchange in an attempt to alleviate congestion. In 2011 an outcropping of Pennsylvanian Jackfork Formation

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

and surrounding

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...

was discovered in the southeast quadrant of the project. The formation was estimated to weigh about 5 million pounds. Due to the size and hardness of the sandstone it was decided to leave the unique and distinctive formation in place as a landmark, rather than use explosives or some other method to try to remove it, and it was dubbed "The Big Rock". When the original I-430 and I-630 interchange was constructed, about 14,000 vehicles a day traveled down each Interstate, and I-630 ended at a traffic signal at Shackleford Road. With expansion and growth in west Little Rock, and particularly in the Chenal Valley neighborhood, the interchange had become progressively more congested by the early 2000s. In 2004 the

Arkansas Highway and Transportation Department The Arkansas Department of Transportation (ARDOT), formerly the Arkansas Highway and Transportation Department, is a government department in the U.S. state of Arkansas. Its mission is to provide a safe, efficient, aesthetically pleasing and env ...

began a study to expand the interchange. The first of three phases began January 2009. First phase was construction of an additional I-630 west to I-430 north lane, modification to Financial Centre Parkway (provides access to Chenal Parkway) just west of Shackleford Road, and an additional traffic signal added to Hermitage Drive. Phase two involved preparing the interchange for future work and mainly involved the I-430 bridge over I-630 which was lengthened. Phase three completed the flyover lanes. The $150 million makeover took over six years to complete. Since construction ended, over 200,000 vehicles use the interchange daily.

Sources

Arkansas Highways

Arkansas Online

AMP

Arkansas Geological
Transportation in Arkansas Interstate 30 Interstate Highways in Arkansas Transportation in Little Rock, Arkansas Transportation in Pulaski County, Arkansas Road interchanges in the United States {{Arkansas-road-stub