State Route 300 (abbreviated SR 300) is a four-lane controlled-access expressway inside of Memphis, Tennessee that goes from Interstate 40 to U.S. Highway 51.
 SR 300 is unsigned throughout its length except on mileposts.
 The exit signs on I-40 just refer to SR 300 as Exit 2A going to Highway 51 and Millington.
 SR 300 carries a 55 mph speed limit.
 Local media sometimes refers to this short route as the "101 Connector", its former federal aid urban designation (U-101 connector).
 I-69 overlaps TN 300 for its entire length.
 It is to be soon erased from the highway system as I-69 will take it over.
Road speed limits in Ireland apply on all public roads in the state.
 These are signposted and legislated for in kilometres per hour.
 Speed limits are demarcated by regulatory road signs.
 These consist of white circular signs with a red outline.
 Speed limits are marked in black with "km/h" below the speed limit.
 Smaller "repeater" speed limit signs are used along stretches of road where there is no change in speed limit, in order to remind motorists currently on the road and to inform traffic merging from junctions that a certain speed limit applies.
French roads have a variable speed limit that depends on weather conditions.
 In dry weather rural 2- or 3-lane roads are limited to 90 km/h, 4-lane expressways (in rural areas) 110 km/h, and highways (in rural areas, when classified as motorway) 130 km/h.
 When raining, the limits are lowered to (respectively) 80, 100, and 110 km/h.
 Urban speed limit of 50 km/h is unaffected by weather.
 The general speed limit is lowered to 50 km/h on all roads in the fog or other low-visibility conditions if visibility is under 50 metres.
Newfoundland and Labrador Route 220 is the southern portion of the Heritage Run in the Canadian province of Newfoundland and Labrador.
 It is a loop road, running due south from the town of Marystown and continues until the town of Grand Bank where it transitions into Route 210 - and vice versa.
 The speed limit along much of Route 220 is 80 km/h, except in communities where the speed limit is reduced to 50 km/h (however, through the town of Fortune, the speed limit is reduced to 30 km/h).
Interstate 75 (I-75) is a part of the Interstate Highway System and runs from the Hialeah–Miami Lakes border, a few miles northwest of Miami, to Sault Ste. Marie in the Upper Peninsula of Michigan.
 I-75 begins its national northward journey near Miami, running along the western parts of the Miami metropolitan area before traveling westward across Alligator Alley (also known as Everglades Parkway), resuming its northward direction in Naples, running along Florida's Gulf Coast, passing the cities of Fort Myers, Punta Gorda, Venice, Sarasota, and the Tampa Bay Area, before turning inward towards Ocala, Gainesville, and Lake City before leaving the state and entering Georgia.
 I-75 runs for 471 mi in Florida, making it the longest interstate in any state east of the Mississippi River.
 The interstate maintains a speed limit of 70 mph for its entire length in Florida.
Zuber is an unincorporated community in Marion County, Florida, United States.
 It is located near the intersection of State Road 326 and County Road 25A.
 Its commerce is supported by its proximity to Interstate 75.
An advisory speed limit is a speed recommendation by a governing body, used when it may be non-obvious to the driver that the safe speed is below the legal speed.
 It is a posting which approximates the Basic Speed Law or rule, and is subject to enforcement as such.
 Advisory speed limits are often set in areas with many pedestrians, such as in city centers and outside schools, and on difficult stretches of roads, such as on tight corners or through roadworks.
 While travelling above the advisory speed limit is not illegal per se, it may be negligence per se and liability for any collisions that occur as a result of traveling above the limit can be placed partially or entirely on the person exceeding the advisory speed limit.
Speed limits in the Czech Republic vary depending on the type of road, and whether the road is within a settlement or not.
 The top speed limit is for motorways outside of settlements, whereas on regular roads within a settlement the speed limit is .
 outside of the settlement and other than motorway the speed limit is 90 km/H.
 Various other special restrictions are applied for certain types and weight categories of vehicle.
The speed limit in localities is set at 50 km/h, but the owner of the road (usually the state) can apply for permission to raise it up to 80 km/h for automobiles and motorcycles or decrease it as low as 10 km/h for tramways and 30 km/h for automobiles.
 It is because of this that some city boulevards have a speed limit of 60 km/h, and some National Road stretches that pass through villages have a speed limit of 70 km/h.
Had Laju Kebangsaan (National Speed Limits) is a set of speed limits applicable on Malaysian expressways, federal roads, state roads and municipal roads.
 The National Speed Limits was enforced on 1 February 1989 following the National Speed Limit Orders 1989 "(Perintah Had Laju Kebangsaan 1989)".
 Like any other countries in the world, failing to obey the speed limit on Malaysian roads and expressways is an offence as subject to Malaysian Road Safety Act 1987, which can be fined up to RM300, depending on the difference between the speed limit and the driven speed.

Question: The commerce of Zuber, Florida is supported by its proximity to an interstate that has what speed limit for its entire length in Florida?
Answer: 70 mph