within the Middletown Historic District. The highway passes through the Airview Historic District before leaving the town limits. East of Middletown, US 40 Alternate passes through a suburban area then begins to ascend Braddock Mountain. The highway gains a climbing lane eastbound to the top of the mountain, which contains the community of Braddock Heights. On the descent of Braddock Mountain, US 40 Alternate expands to a four-lane road, with one lane eastbound, two lanes westbound, and a center turn lane. At the base of the mountain, the alternate route temporarily expands to a four-lane divided highway through its half-diamond interchange with I-70, which has ramps to and from the direction of Frederick. East of I-70, US 40 Alternate reduces to two lanes and passes the Highland Lodge. The alternate route reaches its eastern terminus at a partial intersection with US 40 (Patrick Street) at the western edge of Frederick and the Frederick Golden Mile, a heavily commercialized area east to US 15 (Frederick Freeway). There is no direct access from eastbound US 40 Alternate to westbound US 40 or from eastbound US 40 to the westbound alternate route; those movements are made by using Old Camp Road. History Early paths and turnpikes The portion of US 40 Alternate between Frederick and Boonsboro roughly follows the Monocacy Road, a pack-horse trail blazed by settlers from Pennsylvania around 1730. The trail connected Philadelphia, Lancaster, and Hanover with Winchester, Virginia by way of what is now Taneytown, Frederick, Boonsboro, and Williamsport. The portion of the Monocacy Road from Frederick to Williamsport was used by the Braddock Expedition on its way from Alexandria to Cumberland to commence its ill-fated assault on Fort Duquesne. Following the founding of Hagerstown in 1762, a road was laid out north from Boonsboro to connect the new town with the eastern part of the colony. While the Monocacy Road as a whole was disused by 1794, the portion followed by US 40 Alternate remained an important connection between Baltimore and Western Maryland. The Baltimore and Fredericktown Turnpike Company was chartered in 1805 to build a road along the path from Baltimore to Boonsboro. This turnpike was the first step in connecting Baltimore with Cumberland, the eastern terminus of the just-commenced National Road. By 1808, the turnpike had been completed west from Baltimore and another was under construction. The Baltimore and Fredericktown Turnpike was completed in 1812. That same