Transforming 1930s Urban Roadway Design to Support Today’s Urban Redevelopment

Redevelopment in older urban communities to provide more beneficial built environments must also include redeveloping aging roadways and underlying infrastructure so that those new benefits are fully accessible. This was true in downtown Memphis, Tennessee, where EnSafe helped the Memphis and Shelby County Community Redevelopment Agency improve a 1,810-foot section of Front Street to keep pace with area growth.  The project involved roadway improvements, replacing aging utility infrastructure, and providing a facelift for Front Street’s streetscape. We utilized our best professionals, called upon the area’s strongest firms to consult with us, learned invaluable lessons from significant bumps in the road (yes, pun intended), and, in the end, earned ample kudos for a job well done from our client:

“EnSafe’s design work on the CRA’s Front Street Infrastructure project was extremely responsive to a tight deadline and was quickly approved by the City of Memphis so we could meet the construction schedule. To this point, their design has been implemented with no change orders. Moreover, Chris Triplett’s leadership on this project, and many others for the CRA, has proven a true value to our mission, vision, and goals.” – April Simmons, Director of Vision and Project Management (ret), CRA of Memphis and Shelby County

"EnSafe has and continues to provide outstanding project management and engineering services for the CRA projects. Their vision and attention to details has helped the CRA staff develop potential projects and to keep the projects on track from concept through construction. EnSafe has also provided excellent engineering design services for critical projects with extremely tight deadlines. Their support has played a key role in the management and execution of CRA's projects." - Rosalyn Willis, President (ret), Community Redevelop Agency of Memphis and Shelby County

Our Top Four Planning Considerations

The Front Street project provides a great example of the top four elements our engineers focus on when planning a complete urban street design and construction:

  1. first and foremost, safety,
  2. efficiency for vehicles, cyclists and pedestrians,
  3. accessibility pathways that adhere to the Americans with Disabilities Act (ADA), and
  4. traffic mitigation through roadway diets that make modern urban roadways more friendly for all users.

This particular section of Front Street was first placed in service in the 1930s to provide access along the Mississippi River’s waterfront for unloading cotton and other goods.  The street was widened multiple times throughout the years to over 50 feet of asphalt between curbs. As industrial uses declined, however, the massive road width became a raceway for vehicular traffic – not the safest, most efficient (for cyclist and pedestrians), most ADA accessible, or most traffic mitigating.

To accomplish safety, efficiency, accessibility and traffic mitigation, EnSafe’s design introduced bump-outs and strategically placed on-street parking. Both of these roadway diet designs force drivers to reduce their speed and enable pedestrians to cross a narrower roadway with greater ease, all while maintaining sufficient traffic flow. Our design also included ADA compliant sidewalks and ramps to increase accessibility, as well as streetscape plantings to create inviting pedestrian spaces.

Fortunately for this section of Front Street, its wide roadway and reduced industrial traffic allowed for major modifications to create a modern urban roadway with traffic mitigation, safety, efficiency and accessibility for all users.

What were those “bumps in the road,” you ask?

Utilities Woes

Roadway rehabilitation projects must always take into consideration aging utilities. But Front Street’s 1930s utility mains, including a tunnel underneath the roadway, were significantly more cumbersome than we could have predicted.  Some of the utility mains were active, some abandoned, some unmapped, some with slipshod installation, and most were well past their service life and undersized for proposed future development.

EnSafe’s new design addressed these issues by consolidating duplicated utilities, which required significant coordination with the city and local utility providers to ensure the localized capacity upgrades were matched by upstream/downstream increases to provide for the additional capacity needs. To further complicate the project, a 48-inch access/private utility tunnel traversed perpendicular under the roadway and was relatively shallow, requiring sections of the tunnel to be removed and replaced with multiple smaller lines to allow for the increased size of the gravity lines.

Roadway Construction Sinkholes

Unpredictable sinkholes are not uncommon during roadway construction, but some are dramatically worse than others, as we learned with the Front Street project. Our unpredictable sinkhole encounter was related to the 4-foot by 4-foot box culvert running parallel under Front Street through which most the storm water in the area flowed. Our efforts to improve stormwater capacity included adding a second 4-foot by 4-foot box culvert adjacent to the exiting culvert. But at the start of the new culvert installation, the existing box culvert collapsed from the weight of the tracked excavator, creating a massive sinkhole in the roadway and causing the project to come to an abrupt stop.  To resume the project quickly and efficiently, EnSafe coordinated with a specialty contractor to install temporary shoring inside the box culvert to hold the weight of the construction equipment and materials. The existing box culvert and shoring held true throughout the entire project and remains in service today.

Competing Interests

The Front Street roadway project’s completion date was firm, as it was tied to a new development project that required roadway space for construction activities by multiple contractors.  That meant our construction administrative services and coordination management between multiple stakeholders – our client, roadway contractors, developers and their contractors, the city, utility providers and construction firms – had to be on target at all times. We accomplished this with extensive, proactive communication, starting with kickoff meetings and then regular status meetings throughout the entire project life cycle.

We also carefully tracked and thoroughly evaluated the ripple effects of change orders (whether major changes such as collapsing box culverts, or minor changes to accommodate field conditions) to help implement remedies to keep the project timeline on track. Moreover, we painstakingly maintained detailed records on field changes and, to ensure field record drawings were updated and to prepare the as-builts for city approval, we utilized additional survey data.  Our efforts to keep all parties informed and the construction project moving forward were diligent and paid off in the end – even through navigating final punch-lists when who damaged what was exponentially harder with multiple contractors on site.

Completing urban roadway construction projects requires a systematic and thorough approach, flexibility and quick thinking to navigate unforeseen obstacles, and a solid communication strategy to mediate competing interests. That’s how we elevated the Front Street project from simply complete to an incredible feat.

Want to learn more about our engineering team? Contact us today!

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Posted in Civil/Design Engineering, Insights/Innovation.