has a relatively straight ramp and is controlled by a traffic light. Running off the road on an entering ramp is much less likely than on an exiting ramp. Metering lights are a common feature on the entering ramps. The junction of Saskatchewan Highway 1 (east-west), Saskatchewan Highway 39 (south, part of the CanAm route) and Saskatchewan Highway 301 (north) is an A4 parclo. Highway 1 serves as the freeway, while Highway 39/301 is the arterial road. B4 The parclo B4 interchange superficially appears to be a mirror image of the parclo A4. However, the B4 design provides freeway-to-arterial ramps without traffic lights, while traffic turning left from the arterial must cross opposing traffic. Although this design has the potential to flood the arterial with more freeway traffic than the parclo A4, one particular advantage is the ability to coordinate the traffic signals on the arterial in both directions independently. This is useful when there is more through-movement traffic on the arterial than turning traffic. North American examples There are B4 designs in Alberta: Deerfoot Trail & 17 Ave in Calgary Macleod Trail & Anderson Road in south Calgary: , resulting in significant delays and frequent accidents, despite the higher maximum speed limit on Anderson Road than Macleod Trail. The style of intersection was made necessary due to the presence of a small private cemetery in one quadrant of the interchange: under Alberta's Cemeteries Act burial sites cannot be seized. Three exist in British Columbia. In addition, the Solomon Pond Road interchange on I-290 in Northborough, Massachusetts, was converted from a B2 interchange to a B4 interchange in the mid-1990s with the construction of the Solomon Pond Mall. Also, the West Road interchange on I-75 in Woodhaven, Michigan, was upgraded from a B2 to a B4 in the mid 1980s after suburban sprawl had made the B2 interchange obsolete. In Indiana, the B4 design along IN 37 at its Bloomington interchange with IN 45/46 was retained when the former route was converted to become I-69's exit 120 in 2018. At least four B4 designs are known to exist in Kentucky: Cumberland Parkway interchange with US 27 north of Somerset, currently six ghost ramps sit on the northeast part of the interchange for anticipation for the Somerset Northern Bypass extention. The US 127 interchange with Interstate 64 in Frankfort. US 127 has a second B4 interchange at the Bluegrass Parkway near