Safe Driving Measures

Safe Driving Measures

Understanding the differences between speed bumps and speed humps is crucial for implementing effective traffic calming measures. While both are designed to slow down traffic and enhance safety, their applications and impacts on vehicles vary significantly. This article delves into the nuances of each, their strategic placement, and complementary traffic calming tools, while also emphasizing the importance of community involvement and post-installation evaluations.

Understanding the Basics: Speed Bumps vs. Speed Humps

Defining Speed Bumps and Their Intended Use

Speed bumps are a common sight in various traffic environments, serving as a simple yet effective method to control vehicle speeds. Speed bumps are designed to be abrupt enough to encourage drivers to slow down to avoid discomfort or potential damage to their vehicles. Typically installed in parking lots, driveways, and private communities, speed bumps are especially useful in areas where pedestrian traffic is high and safety is a paramount concern. The primary goal of speed bumps is to enhance safety by reducing the risk of accidents. They are often strategically placed to ensure that vehicles travel at a safe speed in areas where people are likely to be walking or playing. Here’s a brief overview of their characteristics:
  • Height: Generally between 3 to 4 inches.
  • Length: Extends across the width of the roadway.
  • Material: Commonly made from asphalt, concrete, or rubber.
Speed bumps are a class of traffic calming devices that use vertical deflection to slow motor-vehicle traffic in order to improve safety conditions.
While speed bumps are effective for slowing down traffic, they must be used judiciously to avoid creating unnecessary traffic congestion or discomfort for drivers. It’s important to balance the need for safety with the smooth flow of traffic.

Characterizing Speed Humps and Their Applications

Speed humps are a gentler form of speed control compared to their more abrupt counterparts, speed bumps. Designed to be traversed at lower speeds, they encourage a smoother deceleration and acceleration cycle, making them suitable for residential areas where maintaining a quiet and safe environment is crucial.
  • Gentler Slope: Gradual incline and decline.
  • Wider Span: Covers more of the roadway.
  • Lower Height: Typically three to four inches.
Speed humps are effective in reducing vehicle speeds without causing significant discomfort to drivers or damage to vehicles. They are often used in conjunction with other traffic calming measures to create a comprehensive safety strategy.
Speed humps are strategically placed to ensure that they are visible and provide enough space for vehicles to adjust their speed safely.
Their installation is usually the result of a careful planning process that includes traffic studies and community input. The goal is to achieve a balance between traffic flow and the safety of pedestrians and local residents.

Comparing the Physical Differences and Impact on Vehicles

Speed bumps and speed humps serve similar purposes but differ significantly in design and impact on vehicles. Speed bumps are abrupt and high, typically ranging from 3 to 6 inches in height, which forces vehicles to slow down dramatically to avoid discomfort or vehicle damage. In contrast, speed humps are more gradual and extend across the width of the road, with heights of about 3 to 4 inches, allowing for a smoother transition at lower speeds. The installation costs for these measures can vary, with speed bumps often being more expensive due to their intensive design and material requirements. For example, the cost for installing a speed bump can range from $1,000 to $1,500 per bump.

Strategic Placement of Speed Control Measures

Criteria for Installing Speed Bumps in Private and Public Spaces

When considering the installation of speed bumps, it’s crucial to understand the legal and practical criteria that govern their use. Property ownership plays a pivotal role in determining the legality of installing speed bumps. For private roads, the owner has the discretion to implement such measures, provided they adhere to local regulations and standards. In public spaces, the process is more stringent and typically involves:
  • A traffic study to assess the need and suitability
  • Validation of traffic study results with multiple assessments
  • Community engagement through neighborhood meetings
  • Engineering design and planning
It is essential to ensure that the installation of speed bumps does not impede emergency services, and that their design and placement are optimized for the safety and convenience of all road users.
Following installation, a period of evaluation is necessary to monitor the impact on traffic speed and volume, and to make any required adjustments. This post-installation assessment helps in fine-tuning the traffic calming strategy to achieve the desired outcomes.

Assessing the Suitability of Speed Humps for Residential Areas

When considering the implementation of speed humps in residential areas, it’s crucial to evaluate their impact on the community and traffic flow. Speed humps are designed to be less aggressive than speed bumps, providing a more gradual slowing of vehicles. This makes them particularly suitable for areas where maintaining a low-speed environment is essential for safety, without causing excessive disruption to residents and emergency services.
The goal is to balance the need for effective speed control with the minimization of inconvenience for local residents.
To determine the appropriateness of speed humps, a comprehensive traffic study is often conducted. This study includes collecting data on traffic speed and volume, and assessing the street’s characteristics against a set of criteria. For example, a minimum total score of 50 points may be required to consider traffic calming measures. If the score is less than 50, the city will work with the community to explore alternatives. Following the traffic study, the city may hold neighborhood meetings to gather feedback and ensure that the proposed measures align with the residents’ preferences. The process of assessing suitability also includes revisiting previous requests for traffic calming measures, which may be reconsidered under certain conditions.

Complementary Traffic Calming Tools

Integrating Speed Cushions with Emergency Response Plans

Speed cushions are a strategic compromise in traffic calming, designed to slow down traffic while minimizing impact on emergency response times. They are typically 12 ft long and 3 to 4 in tall, with gaps allowing emergency vehicles to pass through unimpeded. This design ensures that while regular vehicles are forced to reduce speed, emergency vehicles can maintain their speed by straddling the cushions. The installation process involves city engineering staff who will design and develop a plan for the traffic calming measures. A follow-up study, conducted at least 6 months post-installation, is essential to evaluate the effectiveness of the speed cushions and to document any changes in traffic speed and volume. Here is a brief overview of the steps involved in the integration process:
  • Conduct a preliminary traffic study to assess the need for speed cushions.
  • Design the speed cushion layout with emergency vehicle access in mind.
  • Install the speed cushions and inform local emergency services of their locations.
  • Perform a follow-up study to measure impact and make necessary adjustments.

Raised Crosswalks: Enhancing Pedestrian Safety

Raised crosswalks serve as a dual-purpose solution for traffic calming and pedestrian safety. With a 10 ft wide flat top, these installations ensure that pedestrians are more visible to approaching drivers, naturally encouraging slower vehicle speeds. The typical dimensions of a raised crosswalk include a length of 22 ft and a height of 3 inches, conforming to city crosswalk policies. In addition to their safety features, raised crosswalks offer a physical reminder for drivers to reduce speed, similar to speed cushions but with the added benefit of a pedestrian crossing point. The design of raised crosswalks integrates seamlessly with the surrounding infrastructure, often requiring minimal additional signage or road markings. Below is a list of traffic calming tools that complement raised crosswalks:
  • Speed Cushion
  • Traffic Circle
  • Mini Roundabout
  • Choker
  • Chicane
  • Bulb-out
  • Radar speed sign
  • Striping
Each of these tools plays a unique role in managing vehicle speeds and enhancing pedestrian safety, forming a comprehensive approach to traffic calming.

The Effectiveness of Traffic Circles in Managing Flow

Traffic circles, also known as roundabouts, have become a cornerstone in modern traffic management. Their design inherently promotes a continuous flow of traffic, significantly reducing the likelihood of congestion and accidents. The circular flow of traffic in roundabouts reduces the stop-and-go patterns seen at traditional traffic signals, which is not only more efficient but also decreases vehicle emissions due to less idling. The benefits of traffic circles extend beyond improved traffic efficiency; they also enhance safety. By simplifying the decision-making process at intersections and virtually eliminating the possibility of head-on or high-speed right-angle collisions, roundabouts contribute to a lower incidence of severe accidents. Here is a list of additional advantages:
  • Improved safety for pedestrians and cyclists
  • Aesthetic enhancements to the community
  • Potential for reduced long-term maintenance costs compared to signalized intersections
It is crucial to monitor the performance of traffic circles post-installation. Data on traffic speed and volume should be collected at least six months after implementation to ensure that the traffic calming measures are meeting their intended goals.

Post-Installation: Monitoring and Adjustments

Conducting Follow-up Studies to Assess Impact

After the implementation of traffic calming measures, it is crucial to conduct follow-up studies to gauge their effectiveness. A follow-up study should occur at least 6 months after installation, allowing for an accurate assessment of changes in traffic behavior. Data on traffic speed and volume are collected to document any variations on the treated streets. Validation of the initial traffic study results is essential. To ensure reliability, at least two speed studies, spaced a minimum of 8 weeks apart, are required. The second study’s findings must align within 10 percent of the initial results to confirm the impact of the traffic calming measures. If discrepancies arise, a third study may be necessary.
The follow-up studies not only validate the effectiveness of the measures but also inform any necessary adjustments to optimize traffic flow and safety.
In cases where previous requests for traffic calming were not implemented, reconsideration is possible under specific circumstances. This ensures that all community concerns are addressed over time and that the measures in place continue to meet the evolving needs of the neighborhood.

Revisiting Traffic Calming Measures for Continuous Improvement

The lifecycle of traffic calming measures does not end with installation. Continuous improvement is essential to ensure that these measures remain effective and meet the evolving needs of the community. A follow-up study, typically conducted six months post-installation, is crucial for assessing the impact of the measures on traffic speed and volume. This data serves as a benchmark for any necessary adjustments. Reconsideration of previously unimplemented requests may occur when new data or community feedback indicates a change in circumstances. This iterative process is vital for refining traffic calming strategies and enhancing their benefits over time. Here is a structured approach to monitoring and adjusting traffic calming measures:
  1. Collect traffic data post-installation.
  2. Conduct a comparative analysis with pre-installation data.
  3. Engage with the community to gather feedback.
  4. Reassess and modify measures if necessary.
  5. Repeat the evaluation cycle periodically.


In conclusion, understanding the distinction between speed bumps and speed humps is crucial for implementing effective traffic calming measures. While both aim to enhance road safety by reducing vehicle speeds, they serve different environments and have distinct impacts on traffic flow. Speed bumps, with their abrupt design, are more suitable for areas where very low speeds are desired, such as parking lots. Speed humps, being gentler, are better for residential and school zones where smoother traffic slowing is necessary. Additionally, other traffic calming tools like speed cushions, raised crosswalks, and traffic circles contribute to a comprehensive approach to managing vehicle speeds. The careful design, installation, and evaluation of these measures, as well as community involvement, are essential for creating safer streets for all users. By prioritizing safety and incorporating various traffic calming strategies, we can work towards reducing accidents and promoting a culture of safe driving.