CEE 417 Flashcards
Costs for crashes and congestion includes
Property damage
Lost earnings
Lost household production
Medical costs Emergency service Travel delay Administrative costs Legal costs Pain and lost quality of life
Costs for crashes and congestion in dollar
300bn
100bn
Policy implications due to crashes > congestion
Make safety a national priority
Increase investment in proven safety countermeasures
Ensure implementation and evaluation of state highway safety plans
Pass good laws and enforce them
Make vision zero a national goal
Differences between travel demand forecasts and actual ridership
Rail
Inaccurate rail: ~Log(cost) Higher costs-> higher inaccuracy Usually overestimated 160% Half of project 40% difference
Differences between travel demand forecasts and actual ridership
Road
Inaccuracy depends on number of vehicle
Small projects underestimate
3 reasons for travel demand forecast errors
Uncertainty about trip distribution
- realistic forecast vs idealistic policies
Uncertainty about trip generation
- old data
Uncertainty in land use development
- land use implemented vs planned
How to handle congestion
Charge peak hour tolls
- Bad Equity
Greatly expand road capacity
- bad physically and economically
Greatly expand public transport capacity
- very costly
- capacity x4 = -9% cars
Live with congestion
- just wait until it’s free again!
What is triple convergence
Heavily congested road gets expanded:
- other driver come back to peak hours
- commuters go back to car
- other drivers change route back
Heavily congested again
3 distributional frameworks for evaluating costs and benefits
Equity
Ability to pay
Maximum belt
Complete street concept
Transportation policy and design approach to
- plan
- design
- operate
- maintain
Enabling - Safe - Convenient - comfortable Travel and access all age all mode
Local streets alternative
Traffic calming
- Street alignment changed
- barriers
- reduce traffic speed
For safety
Livability
Other public purposes
Local street implementation challenges
Impact on cycling
Emergency vehicles
Impact on volume
Traffic safety:
More walking/cycling…
Arterial alternative
Road diets
Reducing number of lanes
Width of lanes
Works with existing right of way
Reduction in vehicle speed -34% crashes \+23% walking \+30% cycling \+~35% on street parking
Volume remains similar
Arterial implementation challenges
Emergency
Added congestion
Road rage
Badly planned
- busses/mail trucks cause more congestion
Turning lanes busy
Less parking
Compete street implementation challenges
Incorporating diverse land uses is difficult
Priorities of a wide mix of users is complex
Increasing walkability is difficult to achieve
Keep traffic flowing can be issue