What are nine potentially hazardous roadway conditions?
1. Roadway departure hazards
2. Road surface conditions
3. Narrow roadways and bridges
4. Railroad crossings
5. Work zones
6. Intersections
7. Roadway design limitations
8. Roadway access problems
9. Pedestrian and bicycle traffic
1. Roadway departure hazards
Roadway departure involves vehicles collisions with fixed objects on or off the road or rollover of a vehicle occurring on both straight and curved sections of the road. The hazards include steep side slopes, drainage ditches, and narrow shoulders.
2. Road surface conditions
Examples of hazardous road surface conditions include potholes, reduction in surface friction, pavement edge drop-offs, wear, inadequate drainage, and incomplete winter maintenance.
3. Narrow roadways and bridges
Narrow roadways reduce the amount of room to maneuver, making them unsafe in every situation. Bridges are especially hazardous when they are narrower than the approaching roadway, as the drivers are more likely to strike the curbs, approaching vehicles, etc.
4. Railroad crossings
Since trains cannot stop quickly or steer out of the way, collisions with a train and railroad crossings are very hazardous.
5. Work zones
Work zone signs are sometimes disregarded or are poorly marked and hard to see. This in combination with the increased construction workers and equipment on the road, congestion, and changing traffic patterns makes work zones very hazardous.
6. Intersections
Hazards such as obstructions, blind spots, inadequate signage, and confusing turn lanes common at intersections make them dangerous.
7. Roadway design limitations
Increase in population and vehicle miles traveled makes roads that were once designed for fewer cars dangerous as they start to accommodate this increase of traffic. This extra traffic is susceptible to hazards caused by sharp curves and lack of medians.
8. Roadway access problems
Driveways and entrances are dangerous since they require alert drivers prepared to act quickly.
9. Pedestrian and bicycle traffic
Fatalities of pedestrians and bicyclists are increasing as our populations grows and increases; therefore, efforts to control speed and accommodate this pedestrian and bicycle traffic must be implemented.
Typically, which jurisdiction or agency is responsible for Interstate highways?
State Departments of Transportation, local district office, headquarters
Typically, which jurisdiction or agency is responsible for State routes?
State Departments of Transportation, local district office, headquarters
Typically, which jurisdiction or agency is responsible for Federal Park Roads?
National Park Service, Bureau of Indian Affairs, Federal Highway Administration
Typically, which jurisdiction or agency is responsible for Local roadways?
City, county, local Departments of Transportation/Public Works
What 5 steps do highway engineers take to prioritize safety needs?
1. Identify hazardous locations and conditions
2. Conduct a highway safety study
3. Establish priorities for project or policy implementation 4. Schedule and implement safety projects
5. Evaluate safety improvements
What examples are given for practices in improving safety on bridges?
• Widen a bridge
• Construct a new bridge • Upgrade bridge rails
If, during a three-year period there were 4 fatalities and you were to choose to upgrade the bridge rails (reduces by 75%), what would be the expected number of crashes for the next three year period?
4 - (4 x 75%) = 1 fatality
What are 3 methods that can be used to enhance bicyclist on-road visibility from motorists?
1. Enhancing roadway shoulders
2. Encouraging use of exclusive bike lanes 3. Incorporating “Share the Road” signs
What funding sources can be used to address safety problems?
• National Highway System
• Interstate Maintenance Program
• Bridge Rehabilitation and Replacement Program
• Surface Transportation Program
• Congestion Mitigation/Air Quality Improvement Program
Which source is typically used for safety related to Interstate Maintenance?
Interstate Maintenance Program
What 4 methods are most commonly used to identify a particular section on a road?
1. Milepost
2. Reference Point
3. Link Node
4. Coordinate or Geographical Information System
If there are a lot of overturned vehicle crashes in a particular area and it has been determined that the shoulder is inadequate, what possible studies can be performed?
• Determine shoulder dimensions and composition
• Check for shoulder drop-offs
If there are a lot of overturned vehicle crashes in a particular area and it has been determined that the shoulder is inadequate, what safety enhancements can be made?
• Upgrade shoulder surface
• Remove curbing/obstructions
• Widen lane/shoulder
Briefly describe the difference between a Road Safety Audit versus a Traditional Safety Review.
Road Safety Audits (RSAs) are a formal response, whereas a Traditional Safety Review does not produce a formal response. The team in an RSA is a multidisciplinary team independent of the project. In contrast, the team in a Traditional Safety Review is made of people with design experience, usually with some sort of connection to the design team. The RSA goes beyond focusing on divers and considers all road users while accounting for their capabilities and limitations. The concentration of the Traditional Safety Review is on motorized traffic with little consideration for
human factors.
Imagine that you are conducting a Road Safety Audit for a 4-mile rural roadway to be constructed and your design is 40% complete. What RSA Phase and Stage would this Road Safety Audit be considered to be?
Phase: Pre-construction Safety Audits
Stage: Preliminary Design
Do you think that more data might be helpful? What types of data and why?
Yes, other data might be helpful. Increasing the scope (3 or 4 years before and after instead of 1 year) could provide a better picture of what really happened because sometimes the drivers take a while to fully adopt certain improvements. Breaking the data down by injury type could be helpful information to see what types of injuries reduced due to the changes. Finally, comparing the change in population of the subject area to the trend seen in the data could be useful information to present to the client.
Assume that after a Road Safety Audit is completed with a cost of $80,000 for changes are made to improve safety on a 10 mile corridor. Given a table showing the number of crashes in a one year period before changes were made and a one year period after changes were made, Compare the total number of crashes before and after the changes are made, Compare the total economic cost before and after the changes are made, What is the benefit to cost ratio for the improvements?