Note: These numbers are approximations to give a sense of the potential benefits of converting one lane on all Austin arterials to bus lanes or protected bicycle lanes. Further study is needed for more accurate numbers.

1,048 tons

of carbon emissions saved each year

Assumption of total annual miles traveled (based on 2019 transportation mode split in Austin Strategic Mobility Plan * Austin population * average trip lengths of 10, 10, 5, 5, and 10 miles respectively for the below modes):

• Driving: 7,202,040 miles

• Carpool/taxi: 1,430,000 miles

• Transit: 194,890 miles

• Walking: 97,445 miles

• Bicycling: 974,450 miles

Emissions Rates:

• Driving alone: 0.45 pounds CO2 per mile

• Carpooling/Taxi: Assuming a similar rate as driving alone, 0.45 pounds CO2 per mile

• Transit: 0.2 pounds CO2 per passenger-mile

Calculation Steps:

• Calculate carbon emissions for driving alone.

• Calculate carbon emissions for carpooling/taxi.

• Calculate emissions saved by taking transit instead of driving.

• Include carbon emissions savings from walking and bicycling.

Calculations:

• Carbon emissions from driving alone = (7,202,040 miles * 0.45 pounds CO2/mile) / 2,000 pounds per ton = 325.09 tons CO2

• Carbon emissions from carpooling/taxi = (1,430,000 miles * 0.45 pounds CO2/mile) / 2,000 pounds per ton = 64.35 tons CO2

• Emissions saved by taking transit instead of driving = (194,890 miles * (0.45 - 0.2) pounds CO2/mile) / 2,000 pounds per ton = 8.76 tons CO2

• Carbon emissions savings from walking = Carbon emissions from driving alone = 325.09 tons CO2

• Carbon emissions savings from bicycling = Carbon emissions from driving alone = 325.09 tons CO2

Summing up carbon emissions savings for all modes:

Total carbon emissions savings per year = Carbon emissions from driving alone + Carbon emissions from carpooling/taxi + Emissions saved from transit + Carbon emissions savings from walking + Carbon emissions savings from bicycling = 325.09 + 64.35 + 8.76 + 325.09 + 325.09 = 1048.38 tons CO2

Assumptions

• Network length: 110 miles

  • 55 miles for bus lanes

  • 55 miles for protected bike lanes

• Cost per mile for bus lanes: $100k

• Cost per mile for protected bike lanes: $90k

• Labor: 20% of total construction cost

• Design and engineering: 10% of total construction cost

• Equipment and materials: 30% of total construction cost

• Other expenses (permits, contingencies, etc.): 10% of total construction cost

Total construction cost

• Protected bike lanes: 55 miles * $90,000 per mile = $4,950,000

• Bus lanes: 55 miles * $100,000 per mile = $5,500,000

• Total construction cost = $4,950,000 (bike lanes) + $5,500,000 (bus lanes) = $10,450,000

Additional costs

• Labor: 20% of total construction cost = 0.20 * $10,450,000 = $2,090,000

• Design and engineering: 10% of total construction cost = 0.10 * $10,450,000 = $1,045,000

• Equipment and materials: 30% of total construction cost = 0.30 * $10,450,000 = $3,135,000

• Other expenses: 10% of total construction cost = 0.10 * $10,450,000 = $1,045,000

Total project cost

Total project cost = Total construction cost + Additional costs

= $10,450,000 + ($2,090,000 + $1,045,000 + $3,135,000 + $1,045,000)

= $10,450,000 + $7,315,000

= $17,765,000

According to the National Safety Council, the comprehensive cost of a fatality is approximately $1.8 million, and the comprehensive cost of a serious injury is approximately $300,000. Important note: The value of a life lost or injured cannot be quantified.

Total fatalities on City of Austin-owned roadways over past five years = 22 + 33 + 26 + 35 + 28 = 144

Using the rule of thumb that five times the number of fatalities are seriously injured: Total seriously injured over five years = 5 * 144 = 720

Now, let's calculate the total crash costs associated with fatalities and serious injuries:

Total crash costs for fatalities = 144 * $1.8 million

Total crash costs for serious injuries = 720 * $300,000

Total crash costs for fatalities and serious injuries:

• Total crash costs for fatalities = 144 * $1.8 million = $259.2 million

• Total crash costs for serious injuries = 720 * $300,000 = $216 million

• Calculate the combined total crash costs:

• Combined total crash costs = Total crash costs for fatalities + Total crash costs for serious injuries = $259.2 million + $216 million = $475.2 million

Now, we have the combined total crash costs over the last five years in Austin.

1. Compare the total crash costs to the project cost:

• Project cost = $17,765,000

1. Calculate the payback period:

• Payback period = Project cost / Annual crash cost savings

To estimate annual crash cost savings, we need to consider the time frame over which these crash costs are incurred. Let's assume these costs are incurred annually:

• Annual crash cost savings = Combined total crash costs / 5 years

Let's proceed with the calculations.

Apologies for the inconvenience; let's correct the calculation of the payback period.

Given:

• Project cost: $17,765,000

• Combined total crash costs over 5 years: $475.2 million

1. Calculate the annual crash cost savings:

   • Annual crash cost savings = Combined total crash costs / 5 years = $475.2 million / 5 years = $95.04 million per year

2. Calculate the payback period:

   • Payback period = Project cost / Annual crash cost savings = $17,765,000 / $95.04 million per year ≈ 0.187 years

The payback period is approximately 0.187 years, which is equivalent to approximately 2.24 months.