We have a budget just like you!

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Household budget

Whether it’s home improvements, dining out, deciding buying a new car or bicycle, we all need to decide whether the benefits of our choices justify the cost.

Transportation budget

Just like you, MnDOT carefully weighs costs and benefits before deciding how to invest in major improvements to our system. One tool we use is a Benefit Cost Analysis.

Photograph showing household budget
Photograph showing transportation budget

Looking for more detail about Benefit Cost Analysis at MnDOT?

Visit MnDOT's BCA website
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The budget crossroads

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Let’s build an intersection to understand how we make transportation decisions on a budget

Most of us don't manage a complex statewide transportation system. So, to make it easier to explain a Benefit Cost Analysis, let's imagine something we are all more familiar with – a roadway intersection.

Diagram of an average intersection
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Measuring intersection characteristics

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Intersections exist where any two roads cross and there are many different types of intersections in our system. Each type has unique characteristics that make it better or worse for different locations. Before we dive into intersection types, let’s talk about the different characteristics we look at when evaluting projects.

Below are a few examples of what we evaluate.

Safety

How safe it is for people traveling through the intersection

Money

How much money it costs plan, design and build the intersection

Movement

How quickly people and freight are able to move through the intersection

Land

How much physical space is needed for the intersection

Other Characteristics

While we are only looking at four characteristics, in reality MnDOT looks at many more such as accessibility, air and water quality, access to nearby properties, and more!

Putting It All Together

To be able to evaluate it all together, we first convert different characteristics to similar units. In real life, we give everything a dollar value so we can add it all up. In this game, we converted everything to a one to five scale.

1 A little of something
2
3
4
5 A lot of something

Click Next to see how different types of intersections compare.

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Comparing intersection types

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Now, let’s see how different intersections compare.

Below are six common intersection types found in our system. For each type, we converted its characteristics - movement, safety, money and land - to our common one to five scale. This is the basis for calculating benefits and costs.

Click Next to learn how we calculate benefits and costs

Thru-Stop

An intersection with stop signs on the cross road but not on the main road.

Diagram of a Thru-Stop intersection

Safety

1

Money

1

Movement

2

Land

0

All-Way Stop

An intersection with stop signs in all directions.

Diagram of an all-way stop intersection

Safety

2

Money

1

Movement

1

Land

0

Traffic Signal

An intersection with a traffic signal and no special lanes or lights for turning.

Diagram of a Traffic signal intersection

Safety

2

Money

2

Movement

3

Land

0

Traffic Signal and Turn

An intersection with a traffic signal and a separate left turn lane and light.

Diagram of a Traffic signal and turn intersection

Safety

3

Money

3

Movement

4

Land

1

Roundabout

A roundabout with only one lane circulating.

Diagram of a Roundabout intersection

Safety

5

Money

3

Movement

3

Land

2

Multi-Lane Roundabout

A roundabout with at least two lanes circulating.

Diagram of a Multi-Lane Roundabout intersection

Safety

4

Money

4

Movement

4

Land

3

Other Intersections

These are just six common types of intersections in our system.

In reality, there are many more different types, and each one comes with their own unique set of characteristics.

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Calculating benefits and costs

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We calculate benefits and costs by looking at how a proposed project compares to what exists today. We calculate the change in the different characteristics - movement, safety, money and land.

Some changes add overall value, like people being able to move through the intersection more quickly and more safely. These are project benefits. Other changes take away overall value, like having to spend money or use more land. These differences are project costs.

Benefits

Safety Improvement

How much safer all people are traveling through the intersection because of the new or enhanced design compared to what is there today

Time Saved

Time each traveler saves because how much more quickly vehicles are able to move through the new or enhanced intersection compared to what is there today

Costs

Money

How much money it costs plan, design and build the new or enhanced intersection

Additional Land Needed

How much additional land it takes to build the new or enhanced intersection compared to what is there today

Click Next to play the game and learn how engineers and planners decide which option meets the needs of a location and provides the most benefits at the least cost!

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Choose a scenario

Back

Choosing the best intersection depends on a lot of things like where it's located, how it's used and what is nearby. Click on a scenario below to explore intersection options for each location and choose the best fit.

Main Street Upgrades

The intersection of Main Street and First Avenue needs an improvement.

Explore options!

Industrial Development

A new industrial development is being built off of the highway about five miles out of town.

Explore options!
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Explore a scenario

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Learn a little more about the scenario, then keep reading and select the solution that you think will work best.

Main Street Upgrades

Scenario Overview: The intersection of Main Street and First Avenue needs an improvement.

Intersection Type: This is currently an all-way stop.

Traffic consistently backs up in every direction causing people to wait.

Diagram of an all-way intersection

Current Conditions:

Safety

2

Money

1

Movement

1

Land

0

Goal: Move travelers through the intersection more quickly.

Things to keep in mind:

Speed limits on the intersecting roads area low so there is a low risk of severe crashes

There is a lot of development at the intersection so using more land will be difficult and expensive

A lot of people walk in this location and it’s important to maintain a safe and comfortable environment for people walking and rolling

Which would you choose to improve Main Street?

Thru-Stop

Diagram of a thru-stop intersection
Summary:

Switching from an all-way stop to a thru-stop doesn’t add any overall benefits. Cars will move through the intersection a little faster but it will be less safe for people driving, walking, and bicycling.

Benefits:
Safety Improvement
-1
Time Saved
+1
TOTAL
0
Costs:
Money to Build
+1
Land Needed
0
TOTAL
1
Confirm Selection

Traffic Signal

Diagram of a traffic signal intersection
Summary:

Adding a signal will save some travel time though it won’t be any safer. The improvement is small but so is the cost. The benefits and costs balance.

Benefits:
Safety Improvement
0
Time Saved
+2
TOTAL
2
Costs:
Money to Build
+2
Land Needed
0
TOTAL
2
Confirm Selection

Traffic Signal and Turn

Diagram of a traffic signal and turn intersection
Summary:

Adding a signal and turn lanes will save a lot of travel time and improve safety a little. The wider road will increase the distance people walking and bicycling have to cross to get to the other side. It's not cheap but the benefits and costs balance.

Benefits:
Safety Improvement
+1
Time Saved
+3
TOTAL
4
Costs:
Money to Build
+3
Land Needed
+1
TOTAL
4
Confirm Selection

Roundabout

Diagram of a roundabout intersection
Summary:

Building a roundabout will save some travel time and improve safety a lot. Roundabouts include refuge islands for pedestrians, but not everyone feels comfortable walking through roundabouts. People bicycling may not be comfortable riding through the roundabout and may choose to use sidewalks to get around. It’s not cheap and will require taking some land, but the benefits and costs balance.

Benefits:
Safety Improvement
+3
Time Saved
+2
TOTAL
5
Costs:
Money to Build
+3
Land Needed
+2
TOTAL
5
Confirm Selection

Multi-Lane Roundabout

Diagram of a multi-lane roundabout intersection
Summary:

Building a multi-lane roundabout will save a lot of travel time and improve safety somewhat. Multilane roundabouts have refuge islands for pedestrians, but the extra travel lanes will increase the distance pedestrians need to cross and make the intersection less safe for pedestrians. People bicycling may not be comfortable riding through the roundabout and may choose to use sidewalks to get around. However, the costs to build it and the additional land needed outweigh the benefits.

Benefits:
Safety Improvement
+2
Time Saved
+3
TOTAL
5
Costs:
Money to Build
+4
Land Needed
+3
TOTAL
7
Confirm Selection

Learn a little more about the scenario, then keep reading and select the solution that you think will work best.

Industrial Development

Scenario Overview: The intersection near the new development outside of town needs an improvement.

Intersection Type: This is currently an thru-stop.

Traffic on the main road doesn’t stop so vehicles have to wait a long time to turn on/off or cross

Diagram of an thru-stop intersection

Current Conditions:

Safety

1

Money

1

Movement

2

Land

1

Goal: Reduce the time it takes for vehicles to turn on/off and cross the main road and improve safety.

Things to keep in mind:

This intersection is outside of town where MnDOT owns a lot of right of way so most intersections won’t require additional land

There is only a lot of turning and crossing traffic at a couple times during the day

The speed limit on the main road is high so there is a high risk of severe crashes

While not as common as on Main Street, people do walk in this location

Which would you choose to improve the intersection?

All-way Stop

Diagram of a all-way stop intersection
Summary:

Switching from a thru-stop to an all-way stop doesn’t doesn’t add any overall benefits. The intersection will be safer but cars will move through more slowly.

Benefits:
Safety Improvement
+1
Time Saved
-1
TOTAL
0
Costs:
Money to Build
+1
Land Needed
0
TOTAL
1
Confirm Selection

Traffic Signal

Diagram of a traffic signal intersection
Summary:

Adding a traffic signal will save travel time and improve safety a little. It will also provide opportunities for people walking and bicycling to cross. It's not cheap, but the benefits and costs balance.

Benefits:
Safety Improvement
+1
Time Saved
+1
TOTAL
2
Costs:
Money to Build
+2
Land Needed
0
TOTAL
2
Confirm Selection

Traffic Signal and Turn

Diagram of a traffic signal and turn intersection
Summary:

Adding a signal and turn lanes will save travel time and improve safety somewhat. It will also provide opportunities for people walking and bicycling to cross, but the wider road will increase the distance they have to cross to get to the other side. It provides more benefits than costs.

Benefits:
Safety Improvement
+2
Time Saved
+2
TOTAL
4
Costs:
Money to Build
+3
Land Needed
0
TOTAL
3
Confirm Selection

Roundabout

Diagram of a roundabout intersection
Summary:

Building a roundabout will save a little travel time and improve safety a lot. It will add refuge islands for pedestrians crossing at the intersection. People bicycling may not be comfortable riding through the roundabout and may choose to use sidewalks to get around. It provides more benefits than costs.

Benefits:
Safety Improvement
+4
Time Saved
+1
TOTAL
5
Costs:
Money to Build
+3
Land Needed
0
TOTAL
3
Confirm Selection

Multi-Lane Roundabout

Diagram of a multi-lane roundabout intersection
Summary:

Building a multi-lane roundabout will save some travel time and improve safety a lot. Multilane roundabouts have refuge islands for pedestrians, but the extra travel lanes will increase the distance pedestrians need to cross and may make the intersection less safe for pedestrians. People bicycling may not be comfortable riding through the roundabout and may choose to use sidewalks to get around. It provides more benefits than costs.

Benefits:
Safety Improvement
+3
Time Saved
+2
TOTAL
5
Costs:
Money to Build
+4
Land Needed
0
TOTAL
4
Confirm Selection
Back

Explore a scenario

Back

How well does your solution work for this scenario?

Main Street Upgrades

You Selected: a Thru-Stop Intersection

Solution Rating:
Not Viable
Considerations:

This solution is not considered viable because the benefits don’t equal or outweigh the costs.

Diagram of a thru-stop intersection
Summary:

Switching from an all-way stop to a thru-stop doesn’t add any overall benefits. Cars will move through the intersection a little faster but it will be less safe for people driving, walking, and bicycling.

Benefits:
Safety Improvement
-1
Time Saved
+1
TOTAL
0
Costs:
Money to Build
+1
Land Needed
0
TOTAL
1
Choose a different solution?

STATEWIDE SCALE:

This analysis was just for one intersection. Did you know? MnDOT has roughly 22,000 intersections and 800 interchanges in its system. We do this type of analysis to help us decide what to build where.

Explore another scenario:

Industrial Development

A new industrial development is being built off of the highway about five miles out of town.

Explore options!
Return to the Street Smart System Homepage

How well does your solution work for this scenario?

Main Street Upgrades

You Selected: a Traffic Signal Intersection

Solution Rating:
Viable
Considerations:

This solution is considered viable but so are others. Remember to consider the points below before making your final choice.

Speed limits on the intersecting roads area low so there is a low risk of severe crashes

There is a lot of development at the intersection so using more land will be difficult and expensive

A lot of people walk in this location and it’s important to maintain a safe and comfortable environment for people walking and rolling

Diagram of an traffic signal and turn intersection
Summary:

Adding a signal will save some travel time though it won’t be any safer. The improvement is small but so is the cost. The benefits and costs balance.

Benefits:
Safety Improvement
0
Time Saved
+2
TOTAL
2
Costs:
Money to Build
+2
Land Needed
0
TOTAL
2
Choose a different solution?

STATEWIDE SCALE:

This analysis was just for one intersection. Did you know? MnDOT has roughly 22,000 intersections and 800 interchanges in its system. We do this type of analysis to help us decide what to build where.

Explore another scenario:

Industrial Development

A new industrial development is being built off of the highway about five miles out of town.

Explore options!
Return to the Street Smart System Homepage

How well does your solution work for this scenario?

Main Street Upgrades

You Selected: a Traffic Signal and Turn Intersection

Solution Rating:
Viable
Considerations:

This solution is considered viable but so are others. Remember to consider the points below before making your final choice.

Speed limits on the intersecting roads area low so there is a low risk of severe crashes

There is a lot of development at the intersection so using more land will be difficult and expensive

A lot of people walk in this location and it’s important to maintain a safe and comfortable environment for people walking and rolling

Diagram of an traffic signal and turn intersection
Summary:

Adding a signal and turn lanes will save a lot of travel time and improve safety a little. The wider road will increase the distance people walking and bicycling have to cross to get to the other side. It's not cheap but the benefits and costs balance.

Benefits:
Safety Improvement
+1
Time Saved
+3
TOTAL
4
Costs:
Money to Build
+3
Land Needed
+1
TOTAL
4
Choose a different solution?

STATEWIDE SCALE:

This analysis was just for one intersection. Did you know? MnDOT has roughly 22,000 intersections and 800 interchanges in its system. We do this type of analysis to help us decide what to build where.

Explore another scenario:

Industrial Development

A new industrial development is being built off of the highway about five miles out of town.

Explore options!
Return to the Street Smart System Homepage

How well does your solution work for this scenario?

Main Street Upgrades

You Selected: a Roundabout

Solution Rating:
Viable
Considerations:

This solution is considered viable but so are others. Remember to consider the points below before making your final choice.

Speed limits on the intersecting roads area low so there is a low risk of severe crashes

There is a lot of development at the intersection so using more land will be difficult and expensive

A lot of people walk in this location and it’s important to maintain a safe and comfortable environment for people walking and rolling

Diagram of a roundabout intersection
Summary:

Building a roundabout will save some travel time and improve safety a lot. Roundabouts include refuge islands for pedestrians, but not everyone feels comfortable walking through roundabouts. People bicycling may not be comfortable riding through the roundabout and may choose to use sidewalks to get around. It’s not cheap and will require taking some land, but the benefits and costs balance.

Benefits:
Safety Improvement
+3
Time Saved
+2
TOTAL
5
Costs:
Money to Build
+3
Land Needed
+2
TOTAL
5
Choose a different solution?

STATEWIDE SCALE:

This analysis was just for one intersection. Did you know? MnDOT has roughly 22,000 intersections and 800 interchanges in its system. We do this type of analysis to help us decide what to build where.

Explore another scenario:

Industrial Development

A new industrial development is being built off of the highway about five miles out of town.

Explore options!
Return to the Street Smart System Homepage

How well does your solution work for this scenario?

Main Street Upgrades

You Selected: a Multi-Lane Roundabout

Solution Rating:
Not Viable
Considerations:

This solution is not considered viable because the benefits don’t equal or outweigh the costs.

Diagram of a multilane roundabout intersection
Summary:

Building a multi-lane roundabout will save a lot of travel time and improve safety somewhat. Multilane roundabouts have refuge islands for pedestrians, but the extra travel lanes will increase the distance pedestrians need to cross and make the intersection less safe for pedestrians. People bicycling may not be comfortable riding through the roundabout and may choose to use sidewalks to get around. However, the costs to build it and the additional land needed outweigh the benefits.

Benefits:
Safety Improvement
+2
Time Saved
+3
TOTAL
5
Costs:
Money to Build
+4
Land Needed
+3
TOTAL
7
Choose a different solution?

STATEWIDE SCALE:

This analysis was just for one intersection. Did you know? MnDOT has roughly 22,000 intersections and 800 interchanges in its system. We do this type of analysis to help us decide what to build where.

Explore another scenario:

Industrial Development

A new industrial development is being built off of the highway about five miles out of town.

Explore options!
Return to the Street Smart System Homepage

How well does your solution work for this scenario?

Industrial Development

You Selected: a Thru-Stop Intersection

Solution Rating:
Not Viable
Considerations:

This solution is not considered viable because the benefits don’t equal or outweigh the costs.

Diagram of an all-way intersection
Summary:

Switching from a thru-stop to an all-way stop doesn’t doesn’t add any overall benefits. The intersection will be safer but cars will move through more slowly.

Benefits:
Safety Improvement
+1
Time Saved
-1
TOTAL
0
Costs:
Money to Build
+1
Land Needed
0
TOTAL
1
Choose a different solution?

STATEWIDE SCALE:

This analysis was just for one intersection. Did you know? MnDOT has roughly 22,000 intersections and 800 interchanges in its system. We do this type of analysis to help us decide what to build where.

Explore another scenario:

Main Street Upgrades

The intersection of Main Street and First Avenue needs an improvement.

Explore options!
Return to the Street Smart System Homepage

How well does your solution work for this scenario?

Industrial Development

You Selected: a Traffic Signal Intersection

Solution Rating:
Viable
Considerations:

This solution is considered viable but so are others. Remember to consider the points below before making your final choice.

This intersection is outside of town where MnDOT owns a lot of right of way so most intersections won’t require additional land

There is only a lot of turning and crossing traffic at a couple times during the day

The speed limit on the main road is high so there is a high risk of severe crashes

While not as common as on Main Street, people do walk in this location

Diagram of an traffic signal intersection
Summary:

Adding a traffic signal will save travel time and improve safety a little. It will also provide opportunities for people walking and bicycling to cross. It's not cheap, but the benefits and costs balance.

Benefits:
Safety Improvement
+1
Time Saved
+1
TOTAL
2
Costs:
Money to Build
+2
Land Needed
0
TOTAL
2
Choose a different solution?

STATEWIDE SCALE:

This analysis was just for one intersection. Did you know? MnDOT has roughly 22,000 intersections and 800 interchanges in its system. We do this type of analysis to help us decide what to build where.

Explore another scenario:

Main Street Upgrades

The intersection of Main Street and First Avenue needs an improvement.

Explore options!
Return to the Street Smart System Homepage

How well does your solution work for this scenario?

Industrial Development

You Selected: a Traffic Signal and Turn Intersection

Solution Rating:
Viable
Considerations:

This solution is considered viable but so are others. Remember to consider the points below before making your final choice.

This intersection is outside of town where MnDOT owns a lot of right of way so most intersections won’t require additional land

There is only a lot of turning and crossing traffic at a couple times during the day

The speed limit on the main road is high so there is a high risk of severe crashes

While not as common as on Main Street, people do walk in this location

Diagram of an traffic signal and turn intersection
Summary:

Adding a signal and turn lanes will save travel time and improve safety somewhat. It will also provide opportunities for people walking and bicycling to cross, but the wider road will increase the distance they have to cross to get to the other side. It provides more benefits than costs.

Benefits:
Safety Improvement
+2
Time Saved
+2
TOTAL
4
Costs:
Money to Build
+3
Land Needed
0
TOTAL
3
Choose a different solution?

STATEWIDE SCALE:

This analysis was just for one intersection. Did you know? MnDOT has roughly 22,000 intersections and 800 interchanges in its system. We do this type of analysis to help us decide what to build where.

Explore another scenario:

Main Street Upgrades

The intersection of Main Street and First Avenue needs an improvement.

Explore options!
Return to the Street Smart System Homepage

How well does your solution work for this scenario?

Industrial Development

You Selected: a Roundabout

Solution Rating:
Viable
Considerations:

This solution is considered viable but so are others. Remember to consider the points below before making your final choice.

This intersection is outside of town where MnDOT owns a lot of right of way so most intersections won’t require additional land

There is only a lot of turning and crossing traffic at a couple times during the day

The speed limit on the main road is high so there is a high risk of severe crashes

While not as common as on Main Street, people do walk in this location

Diagram of a roundabout intersection
Summary:

Building a roundabout will save a little travel time and improve safety a lot. It will add refuge islands for pedestrians crossing at the intersection. People bicycling may not be comfortable riding through the roundabout and may choose to use sidewalks to get around. It provides more benefits than costs.

Benefits:
Safety Improvement
+4
Time Saved
+1
TOTAL
5
Costs:
Money to Build
+3
Land Needed
0
TOTAL
3
Choose a different solution?

STATEWIDE SCALE:

This analysis was just for one intersection. Did you know? MnDOT has roughly 22,000 intersections and 800 interchanges in its system. We do this type of analysis to help us decide what to build where.

Explore another scenario:

Main Street Upgrades

The intersection of Main Street and First Avenue needs an improvement.

Explore options!
Return to the Street Smart System Homepage

How well does your solution work for this scenario?

Industrial Development

You Selected: a Multi-Lane Roundabout

Solution Rating:
Viable
Considerations:

This solution is considered viable but so are others. Remember to consider the points below before making your final choice.

This intersection is outside of town where MnDOT owns a lot of right of way so most intersections won’t require additional land

There is only a lot of turning and crossing traffic at a couple times during the day

The speed limit on the main road is high so there is a high risk of severe crashes

While not as common as on Main Street, people do walk in this location

Diagram of a multi-lane roundabout intersection
Summary:

Building a multi-lane roundabout will save some travel time and improve safety a lot. Multilane roundabouts have refuge islands for pedestrians, but the extra travel lanes will increase the distance pedestrians need to cross and may make the intersection less safe for pedestrians. People bicycling may not be comfortable riding through the roundabout and may choose to use sidewalks to get around. It provides more benefits than costs.

Benefits:
Safety Improvement
+3
Time Saved
+2
TOTAL
5
Costs:
Money to Build
+4
Land Needed
0
TOTAL
4
Choose a different solution?

STATEWIDE SCALE:

This analysis was just for one intersection. Did you know? MnDOT has roughly 22,000 intersections and 800 interchanges in its system. We do this type of analysis to help us decide what to build where.

Explore another scenario:

Main Street Upgrades

The intersection of Main Street and First Avenue needs an improvement.

Explore options!
Return to the Street Smart System Homepage
Back