The B7045 is a meandering rural road in central Ayrshire.
Heading north
The route starts on the A77 to the south of Minishant and heads southeast, winding across fields and soon going under the Ayr to Stranraer railway line. Turning southward, it slips between low hills as it continues across the fields to meet the B742 at a crossroads. The B7045 maintains priority before a slight bend to the west avoids higher ground which rises up on the left-hand side. A side valley provides a gentle climb towards the farm of Grimmet, after which a minor road to the right heads west to Maybole. Now heading southeast once again, the route squeezes between a couple more low hills and then dips slightly on a long straight across farmland. Another right turn leads south west to the B7023, barely half a mile away but the two routes never meet. The route then crosses a ridge, and winds round the flank of the hill, finding its summit of around 70m, before starting to descend into the valley of the Dyrock Burn.
As it passes a walled cemetery on the right the road bends to the left and, overlooking a burn to the south, it heads towards the small village of Kirkmichael. The route enters on Maybole Road, and curves southwards past a junction onto Straiton Road which is lined with brightly painted cottages. A burn is crossed and then a green gap with playing fields to the left leads to the southern part of the village, where a row of houses stands back on the left before the school. The woodland to the right is part of the grounds of Kirkmichael House. A slight climb then takes the route across a watershed and into Aitkenhead in the valley of the Water of Girvan. The route drops onto the tree lined riverbank at the far end of the tiny village and follows the meandering river upstream for a time. However, as the river doubles back on itself, the road continues ahead and climbs gently round a series of tight bends through woodland and across fields. The gradient seems insufficient to warrant these near hairpins, as the route only gains about 30m in altitude over nearly half a mile.
The route dips slightly to cross the Kelse Burn, and then climbs above Cloncaird Castle which sits down below on the riverside. From here the route of the B7045 remains similar overall to that of the Water of Girvan but it climbs up to higher ground to maintain a straighter course, with a summit of around 120m below Kings Hill. This extra height offers some good views across the rolling hills, most of which are clad with forestry plantations on the upper slopes. Presently the route descends back into the valley through a series of winding bends and enters the village of Straiton. Kirkmichael Road leads into a TOTSO T junction with the B741, where it ends, with the B741 continuing ahead into the village as well as heading west.
History
The route was originally unclassified but had gained its number by 1932. The most notable change to the route since is at the very start where it has been extended slightly along a former section of the A77, after the main road was realigned in the late 1960s to remove a series of bends.