1. Why did the City consider this project?
The King Arthur Boulevard Traffic Calming Project was developed to improve safety for everyone who uses the roadway—including residents, pedestrians, bicyclists, and motorists.
Over many years, the City received concerns from residents regarding speeding along King Arthur Boulevard. Speed studies conducted by the City indicated that vehicle speeds were consistently above the posted speed limit. The measured 85th-percentile speed was approximately 32 mph on a roadway posted at 25 mph, indicating that many drivers were traveling faster than desired for a residential neighborhood.
Rather than relying solely on enforcement, the City selected engineering improvements that encourage drivers to naturally operate at safer speeds while providing better accommodations for all roadway users.
This project is consistent with the City of Lewisville's Complete Streets Policy, adopted in 2022, which encourages streets that safely serve motorists, pedestrians, bicyclists, transit users, children, seniors, and people with disabilities.
2. What information was used to design the project?
The roadway improvements were based on several sources of information, including:
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Resident requests for traffic calming over several years
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Vehicle speed studies
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Traffic volume information
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Crash history
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Existing roadway conditions
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Engineering judgment
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National roadway design guidance
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Complete Streets principles
Roadway design is not based on one factor alone. Engineers evaluate traffic operations, safety, neighborhood context, roadway function, and long-term community goals before selecting appropriate improvements.
3. Did the City involve residents before construction?
Yes.
The City conducted more public outreach than is typical for a roadway striping project.
Outreach included:
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A public meeting in November 2024.
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Mailed invitations to homes along the corridor.
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Project information on the City's website.
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Social media announcements.
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Presentation of roadway plans and cross-sections.
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Opportunities for residents to review the proposed design and provide comments.
Large engineering drawings were displayed during the public meeting so residents could locate their homes and review the proposed improvements in detail.
4. Why is the speed limit 25 mph?
King Arthur Boulevard is classified as a residential collector roadway.
A 25 mph speed limit provides drivers with additional time to react to pedestrians, bicyclists, turning vehicles, and unexpected conflicts commonly found in residential neighborhoods.
Research consistently shows that lower operating speeds reduce both the likelihood of crashes and the severity of injuries when crashes occur.
Although Texas law recognizes the 85th-percentile speed as one consideration when establishing speed limits, that principle primarily applies to setting regulatory speed limits—not to determining whether traffic calming improvements are appropriate. Residential streets often incorporate design features specifically intended to reduce operating speeds closer to the posted speed limit.
5. Why didn't the City simply raise the speed limit?
The City's speed studies found that the 85th-percentile speed was approximately 32 mph while the posted speed limit is 25 mph.
From an engineering perspective, there were two possible approaches:
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Increase the speed limit to better match existing driver behavior, or
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Modify the roadway so drivers naturally travel closer to the intended residential speed.
Because this is a residential neighborhood where safety for residents, pedestrians, and bicyclists is a priority, the City chose to redesign the roadway to encourage lower operating speeds rather than increase the posted speed limit.
6. Why didn't the City leave the road the way it was?
The previous roadway encouraged higher operating speeds because it was significantly wider than necessary.
Roadway design strongly influences driver behavior.
Simply posting a lower speed limit without changing the roadway often has little effect. Engineering studies consistently show that drivers tend to travel at the speed the roadway "feels" comfortable for.
The redesign changes that visual perception so the roadway better matches the intended 25 mph neighborhood environment.
7. Why were the travel lanes narrowed?
Lane width has a significant influence on driver behavior.
Studies by American Association of State Highway and Transportation Officials (AASHTO) and the Federal Highway Administration have shown that slightly narrower travel lanes in low-speed urban environments encourage drivers to travel at more appropriate speeds without significantly affecting traffic operations.
Before the project, portions of King Arthur Boulevard were unusually wide for a residential street. In some areas, each direction provided enough pavement for nearly two vehicles to travel side by side.
The King Arthur Boulevard lanes remain within accepted engineering practice for a 25 mph urban collector roadway. Drivers may initially perceive the roadway as narrower, but after becoming familiar with the corridor, most motorists comfortably operate within the lane.
8. Are the travel lanes actually too narrow?
No.
Although the roadway may appear narrower than before, the travel lanes remain within nationally accepted engineering recommendations.
For urban streets with 25 mph speed limits, AASHTO generally recommends travel lane widths between 10 and 11 feet depending on roadway function.
The King Arthur Boulevard travel lanes are approximately 11.5 feet wide, which falls within accepted engineering practice for this type of roadway while supporting traffic calming objectives.
9. Why didn't the City simply install stop signs to slow traffic?
National engineering guidance and the Texas Manual on Uniform Traffic Control Devices (TMUTCD) specifically state that stop signs shall not be installed for the purpose of reducing vehicle speeds.
Stop signs are intended to assign right-of-way where traffic conflicts exist—not to calm traffic. Installing unnecessary stop signs often causes drivers to ignore them, reducing compliance at locations where stopping is actually critical for safety.
Instead, modern traffic calming focuses on roadway design features that naturally encourage drivers to travel at appropriate speeds.
10. Why were bike lanes added?
The bike lanes are part of the City's Complete Streets vision and provide a dedicated space for people riding bicycles and other permitted micromobility devices.
Providing a designated bicycle space:
• Improves safety by separating bicycles from motor vehicles.
• Encourages healthy transportation choices.
• Connects neighborhoods with parks and trails.
• Improves roadway organization.
• Creates a visual narrowing effect that helps reduce vehicle speeds.
The bike lanes benefit all residents—even those who never ride bicycles—because they contribute to lower vehicle speeds and a more organized roadway.
11. Why are there concrete barriers next to the bike lanes?
The barriers provide additional separation between moving traffic and the bicycle lane.
They help:
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Increase bicyclist comfort.
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Better define the roadway.
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Reduce encroachment into bicycle space.
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Reinforce lower-speed driving behavior.
The barriers are located where additional separation was determined to be beneficial based on roadway geometry and the overall corridor design.
12. Why were concrete separators installed instead of flexible posts?
Several types of protected bike lane separators are available.
The City selected concrete separators because they provide:
Each separator also includes reflective markers to improve nighttime visibility.
Although flexible plastic posts were considered, concrete separators provide a more permanent and durable solution.
13. Why do the bike lanes continue through the section where there are no homes?
Although there are few homes along the section between Morgan Lefay Lane and Old Denton Road, maintaining a consistent roadway configuration provides several important safety benefits.
If the roadway suddenly became wider before the Old Denton Road intersection, drivers would naturally tend to increase speed immediately before reaching one of the busiest intersections along the corridor.
Maintaining a consistent roadway cross-section helps:
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Keep operating speeds lower.
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Reduce driver confusion.
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Provide continuous bicycle accommodations.
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Create predictable lane assignments.
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Improve safety approaching the intersection.
Consistent roadway design is an established engineering best practice and is recommended by AASHTO because drivers respond better to predictable roadway environments than to frequent changes in lane configuration.
14. Why were bump-outs installed?
Curb bump-outs (also called curb extensions) reduce the amount of pavement visible to drivers and create a narrower visual roadway.
Benefits include:
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Lower vehicle speeds.
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Shorter pedestrian crossing distances.
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Improved visibility.
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Better parking organization.
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Reduced crossing exposure.
Even where pedestrian volumes are relatively low today, these features improve long-term safety and support future neighborhood growth.
15. Why were parking lanes added?
Before the project, many residents parked along the edge of the roadway without designated parking spaces.
The project formally defines parking areas in front of residences.
This provides several benefits:
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Clearly defined parking spaces.
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Better separation from moving traffic.
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Improved organization.
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Better protection for parked vehicles.
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Improved access for residents and visitors.
Parking is generally designated only where residential frontage exists. Sections without homes generally do not include parking because there is little parking demand.
16. How does the project improve ADA accessibility?
The project includes improvements that better accommodate residents and visitors with disabilities.
Designated parking areas provide more consistent access to sidewalks and residences while helping maintain accessible travel paths.
Providing ADA-compliant parking is consistent with federal accessibility requirements and supports residents and visitors with disabilities.
The accessible parking spaces are paired with curb ramps and pedestrian access routes to improve overall mobility.
17. Why were changes made near the Old Denton Road intersection?
Intersections require different design considerations than mid-block roadway segments.
Engineers evaluate:
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Traffic volumes
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Turning movements
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Signal operations
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Safety history
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Queue lengths
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Available roadway width
The lane assignments approaching the intersection were designed to balance traffic operations with the project's overall traffic calming objectives while maintaining a consistent corridor design.
18. Why was one of the left-turn lanes removed at Old Denton Road?
Traffic analysis showed that the intersection does not require dual left-turn lanes.
Traffic volumes are well within the capacity of a single left-turn lane, allowing roadway space to be reallocated without creating significant operational impacts.
The revised lane configuration maintains safe and efficient traffic flow while supporting the overall traffic calming goals of the project.
19. Will these improvements actually reduce speeding?
Experience throughout Texas and across the United States shows that roadway design has a significant influence on driver behavior.
Traffic calming measures such as:
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Narrower lanes
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Bicycle lanes
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Visual edge treatments
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Curb extensions
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Parking lanes
have consistently demonstrated reductions in operating speeds without relying solely on police enforcement.
Although drivers may initially react to the new roadway layout, studies show that most motorists adapt within several months, and operating speeds become more consistent.
20. Is this project consistent with engineering standards?
Yes.
The project was developed using nationally recognized engineering guidance and accepted transportation design practices.
Applicable references include:
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Texas Manual on Uniform Traffic Control Devices (TMUTCD)
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AASHTO Green Book
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AASHTO Guide for the Development of Bicycle Facilities
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FHWA Proven Safety Countermeasures
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City of Lewisville Complete Streets Policy
Every roadway is unique, and engineering standards allow designers to select treatments appropriate for the roadway's speed, function, surrounding land use, and community goals.
21. What benefits should residents expect over time?
As drivers become familiar with the new roadway, residents can expect:
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Lower average vehicle speeds.
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Improved safety for all roadway users.
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Better organization of parking.
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Dedicated bicycle facilities.
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Improved neighborhood appearance.
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Increased predictability for drivers.
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Enhanced accessibility.
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Better compliance with the posted speed limit.
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A roadway that better reflects the character of a residential neighborhood.
The City's goal is simple: create a safer King Arthur Boulevard while continuing to provide efficient access for residents, visitors, emergency responders, pedestrians, bicyclists, and motorists alike.
22. How long will it take before the project reaches its intended effect?
Transportation research shows that drivers typically need several months to adjust to a new roadway configuration.
Immediately after construction, drivers tend to be cautious because the roadway is unfamiliar.
After approximately 6 to 9 months, driving behavior stabilizes, allowing engineers to evaluate the long-term effectiveness of the improvements through follow-up speed studies.
If you have additional questions about the project, please contact the City of Lewisville Engineering Department. Staff are committed to providing timely, accurate, and transparent information throughout the project.
