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X91 Bridge Structural Design Services Civil Design Elements While the bridge widening is most significant element of this project, the following civil design elements must be addressed during the design of the project: Roadway Widening The primary widening will occur to the north, which will have an approximate 30 -foot widening. The northwest quadrant of the project location is at grade with the roadway, simplifying the widening with only minimal grading required. However, the northeast quadrant is significantly lower than the existing roadway grade. As the proposed sidewalk will be at the right-of-way, a retaining wall will be required to address the grade differential. The southerly widening is minimal, with a net widening is only 2.5 -feet as the new curb shifts towards the centerline to match up to the Type 26 barrier on the bridge. (See Figure 3) It appears that the widening on the south side will only require regrading of the 2:1 slopes to join existing. 8' 1� I 2.5' 2:1 SLOPE PROPOSED CURB EXISTING CURB Figure 3. South widening will require regrading of the slopes. In addition, all horizontal transitions will be designed to meet design standards on First Street. The proposed curb on the south side of the bridge will actually be 1.5 -feet closer to the centerline than its current location, therefore transitions will be required within the approach to the bridge. River Access Roads The maintenance road/bike lane (Photo 6) along the river will not be impacted with the widening of the bridge, and provisions will be made for any falsework requirements to ensure safe passage and minimum clearances are The access from First Street to the maintenance road will require realignment. On the south side of First Street, the access will require only a minimal change in alignment. The north side is impacted signficantly. The 30.5 - Photo 6. Maintenance road/bike lane clearances will be maintained. DMJM HARRIS AECOM foot widening to the north coupled with the skew of the bridge encroaches 15 -feet into the access road. This will require the relocation of this access'road easterly to clear the bridge widening. The shift in the access road will also require the retaining wall in this quadrant to extend northerly along the mobile home park to support the access road and to address the difference in the elevation. (See Figure 4). Figure 4. The access roads to the river will require realignment due to the bridge widening. Right -of -Way From our research of available documents it appears that adequate right-of-way is available in,all four quadrants. A temporary construction easement will be required in the northeast quadrant for the construction of the retaining wall. It also appears that the mobile homes at that same location have encroached into the City right-of-way and will require removal prior to construction. (Photo 7) Photo 7. The mobile home park has encroached within the City right-of-way.