This document discusses access management strategies to improve traffic flow and safety on arterial roads. It describes how access management preserves traffic capacity and reduces accidents by limiting driveway numbers and conflicts. Techniques include increasing spacing between signals/intersections, managing driveway design and placement, and removing turning vehicles from through lanes. The document emphasizes applying access management guidelines and coordinating with ALDOT early in the permitting process.

1. Wal-Mart
Sub-Regional Meeting
Access Management
ALDOT Permitting
Jim Meads & Randy Braden
Sain Associates, Inc.
May 2, 2007

2. What is Access Management?
 Access management preserves safe and
efficient traffic movement, while allowing
reasonable access to property.
 Sounds easy, but the application to
individual cases is extremely difficult…
especially without an access management
policy.

3. What Does Access Management
Do?
 Preserves street capacity.
 Reduces traffic accidents
 Preserves value of adjacent property
 Manages congestion

4. Access Management Techniques
 Increase spacing between signals and
interchanges
 Driveway location, spacing and design
 Use of exclusive turning lanes
 Median treatments/channelization
 Use of service and frontage roads

5. Typical Arterial
Highway Life Cycle
New
Arterial
Increased
Accessibility
Higher Land Values

6. Arterial Life Cycle
New
Arterial
Increased
Accessibility
Higher Land Values
Increased Changed
Traffic Land Use

7. Arterial Life Cycle
New
Arterial
Demanded! Increased
Deteriorated Accessibility
Level of Service
More Traffic Higher Land Values
Conflicts
Increased Changed
Traffic Land Use

8. Preserving Traffic Flow
Alabama in 2000
 Conclusions
 Alabamians are mobile
 Growing faster than national average
 Few Choices
–Tolerate congestion and crashes
–Massive road building (new revenues)
–Other strategies… access management

9. The Effects of
Poor Access Management
 Congestion, possible gridlock
 Frustrated drivers
 Frequent traffic accidents
 Continuous strip development
 Decreased property values
 Commercial establishments struggling to
survive
 Complaints about congestion, noise, safety
 Pressure on government to improve street

10. The Effects of
Effective Access Management
 Fewer and less severe crashes
 Less stop and go traffic, less delay
 Increased and preserved capacity
 More attractive corridors, livable
communities
 Preservation of private investment in
abutting properties
 Consistency in handling requests for
driveways

11. Access Management Works
 Reduces crashes as much as 50%
 Increases capacity 23-45%
 Reduces travel time and delay by
40-60%
 Extends highway life
 Treats permit applicants consistently
 Decreases fuel consumption by 35%

12. How Do You Apply Access
Management ?
 Limit the number of conflict points
 Separate conflict locations
 Remove turning vehicles from the through
lanes
 Reduce turning movements
 Improve driveway operations

13. Ways to Limit Conflicts
 Purchase access rights
 Non-traversable median
 “Right in, right out”
 Channelization to discourage left
turns
 Remove TWLTL

14. R
 Insert figs 3-1 and 3-2
9 total
conflicts

15. 32 total
conflicts

16. Right in, Right Out
2 Conflicts

17. Separating Conflicts
 Set minimum access spacing, corner
distance, and property line clearance
 Limit number of egresses per
property
 Designate driveway location
 Consolidate access driveways
 Optimize driveway spacing

18. Remove Turn Vehicles
From Thru Lanes
 Left turns are major cause of delay and
major cause of accidents
 Turning vehicles have high speed
differentials (severe collisions)

19. Figure 1-3: Intersection/driveway
traffic crashes by maneuver (NHI, 2003)
16%
27%
47%
10%

20. Removing Turning Vehicles
 Install left-turn deceleration bay at existing
median
 Install raised median with left turn-bays
 Install right-turn deceleration lane
 Install continuous right-turn lane

21. Reducing Turning Movements
Accidents are proportional to traffic
volumes
 Require connections between
parcels
 Require internal circulation
 Require alternate access points
 Require shared access
 Adopt vehicle use limitations
 Many similar treatments

22. Shared Access

23. Improve Driveway Operations
 Adequate sight distance
 Smooth vertical geometry
 Adequate radii
 Adequate throat width and length
 Well signed and marked

24. 6) Improve Driveway Operations
(sample of methods)
Inadequate storage distance
Inadequate Entry Throat Length

25. Access Management Guidelines
When, where and how to provide
access
3) Intersection functional area and
sight distance
4) Turn lanes
5) Median openings
6) Traffic signal spacing
7) Driveway location and design

26. Intersection Functional Areas
Functional area
varies by
approach

27. Turn Lanes
 Allow speed change
 Store turning vehicles
• Left-turn bays
• Right-turn bays
• Acceleration & deceleration lanes
• Warrants
• Design criteria

28. Reducing Conflict Points on an
Arterial

30. Driveway Spacing Illustration

31. Driveways

32. Encourage adjacent properties to
share access
Joint or shared access connections onto a
roadway minimize the number of conflict
points.

33. Coordinate driveway locations on
both sides of the roadway
Align access into a four-leg intersection or on low-
volume low-speed roadways provide sufficient
offset distance to avoid spillback problems.

34. Install driveway channelizing island
to discourage left-turn maneuvers.
Channelizing medians are used to restrict left-
turn movements and limits crossing
conflicts.

35. Maximize corner clearance by
locating access as far from the
intersection as possible
Move or locate driveways as far from an
intersection as possible helps to separate
conflict points and improve safety and

36. Separate left-turn entrances and
exits at major traffic generators
Replaces either one or two full-movement access
connections with two limited-turn connections
with separated left-turn movements

37. Construct or modify median to
allow only left turns from a major
roadway
Reduces the number of conflict points and delays.
Adequate provisions should be made for vehicles
that cannot make direct left-turn exits.

38. ALDOT GOALS
 SAFETY
 Improved access along State Routes
 Efficient permit process
 Clear guidelines

39. ALDOT Structure
MONTGOMERY
Division Division
District District District District

40. Key Items
 Does the District and/or Division have a checklist
for Plans and Permitting? (See Handouts)
 How long does the review take?
 Who do we submit the plans to?
 How many sets?
 Who do we follow up with for status weekly
status updates?
 If the final District Submittal has been there for
longer than a month, call Randy Braden!

41. Best Permitting Practices
 Involve ALDOT EARLY and OFTEN
 Have a site meeting in the concept phase
with the following in attendance:
 Division Traffic Engineer
 District Engineer
 Division Maintenance Engineer
 State Permit Engineer

42. What not to do!