If you'd like to process what you've learned about analyzing risks, making decisions and considering alternatives by applying it to real situations, this page is for you!
If not, feel free to move to the next page -- you can always come back later and play.
What's this all about?
While developing a project for the American Printing House for the Blind, I asked Carlo and Cecilia, two independent travelers who are blind and have normal hearing, to analyze the risks of crossing in three different Situations of Uncertainty.
I chose a variety of situations to reveal the complexity of factors that can affect the analysis, which lead to some surprising results and illustrated the importance of being methodical when considering the risks.
Before we began the analysis, I explained to Carlo and Cecilia all the factors in the Risk Analysis Checklist.
At each crossing, they observed the traffic and how well they could hear it and, if the street was not familiar, they figured out how wide it is.
Then we went through each item on the checklist and they came up with their analysis of the situation, as well as which alternatives might be feasible.
In each case, we did not consider factors that might have existed at other times of the day, such as what might happen at night or during rush hour --
it is important to be able to analyze situations that exist at the time that you consider crossing.
Regarding whether the risks of crossing are acceptable, there is no right or wrong answer -- that is a personal choice.
In the third scenario you'll see that the decision of accepting risk may differ between people, and it may not even be directly related to the level of risk.
What is important is that the decision is informed and well-reasoned, based on objective observations of the important factors that exist at the time the decision is made.
Scenarios Below are videos from the three Situations of Uncertainty, with explanations of the warning time that they had, followed by the results of the analysis by Carlo and Cecilia.
You can either simply read through their analyses, or analyze the situations yourself.
To get some experience analyzing situations yourself: Scroll down to each scenario,
read about the "Warning time of approaching vehicles" and watch the video for that situation. Fill out the Risk Analysis Checklist,
and see how your analysis compares to those of Carlo and Cecilia.
Scenario #1: Clearwater
WARNING TIME OF APPROACHING VEHICLES:
For traffic from the left, there was more than enough warning to be confident it is clear to cross when quiet. From the right there was almost but not quite enough warning of approaching traffic, so it was not possible to be confident that it was clear to cross.
Click here for a written description of the video.
ANALYSIS:
Would Cecilia and Carlo have the right of way at this crossing?
Yes -- it was clearly marked as a crosswalk for pedestrians.
Likelihood that they'd be surprised by an approaching vehicle if they started to cross when quiet:unlikely
Reasoning: Since they had enough warning for vehicles from the left and almost enough for vehicles from the right, when it was quiet the area where a vehicle could be close enough to reach them but not close enough to be heard was small.
So even though traffic volume was moderately high, they considered it unlikely that if they started to cross when it's quiet, there would be an approaching vehicle just out of earshot that could reach them.
If they were surprised, likelihood that the driver would hit them:moderately to extremely unlikely
Factors that indicated the drivers would not be likely to stop for Carlo or Cecilia:
Vehicles were going moderately fast;
Carlo and Cecilia would not be likely to cross with a group of pedestrians.
Factors that indicated the drivers would be likely to stop:
There was only one lane approaching in each direction (no "multiple threats")
Pedestrians were highly expected (crosswalk was very well marked and pedestrians crossed frequently);
Line of sight and visibility were good and the warning time of approaching vehicles was relatively long, so they would not be likely to start their crossing when the driver is too close to avoid hitting them;
Road conditions were good;
They could safely stand with a foot in the street to wait to cross;
They'd be using a cane;
Drivers were observed to stop for most pedestrians.
If they were hit, likelihood of being seriously injured or killed:about 52%
vehicles were going about 30-35 mph (see chart on page 5, or look at the bottom of the front page of your checklist)
Summary: Risk of being seriously injured or killed is relatively low.
If Carlo or Cecilia started to cross when it's quiet, it is unlikely they'd be surprised by an approaching vehicle that could reach them and if that happened, it is very unlikely that it would hit them but if it did, they'd have a relatively high (about 50/50) chance of being seriously injured or killed.
Is the risk acceptable?
Carlo and Cecilia both felt that the risk of crossing in that situation was acceptable.
Feasible alternatives if the risk of crossing was not acceptable:
Get assistance (there are lots of pedestrians crossing who could help).
Cross at another location with better control (there is a traffic signal about a block away).
Get all the drivers to yield:
Since there is only one lane in each direction and a refuge island in the middle, they could wait to cross each half of the street until a driver had stopped for them.
Avoid the crossing, for example by getting a ride.
QUESTION: Does this meet the conditions to be able to use the alternative of being prepared to turn around and return to the curb?
(Click here for the answer)
Scenario #2: Truman Parkway
WARNING TIME OF APPROACHING VEHICLES:
Because of constant ambient sounds from a nearby highway, the vehicles from both directions could not all be heard with enough warning to be confident it was clear to even reach the middle of the street.
Click here for a written description of the video.
ANALYSIS:
Would Cecilia and Carlo have the right of way at this crossing?
No -- This was a mid-block crossing, the only corner nearby was the entrance to a parking lot. However in states where pedestrians with white canes have the right of way everywhere, Carlo and Cecilia would have had the right of way here.
Likelihood that they'd be surprised by an approaching vehicle if they started to cross when quiet:likely
Reasoning: traffic volume was moderately high and since the approaching vehicles couldn't be heard with enough warning to get even half way across the street, the area where a vehicle could be close enough to reach them but not close enough to be heard was relatively large.
If they were surprised, likelihood that the driver would hit them:very likely
Factors that indicated the drivers would not be likely to stop for Carlo or Cecilia:
there were two lanes approaching from the right so there was the possibility of "multiple threats;"
vehicles were going fast;
pedestrians would be completely unexpected (no pedestrians were ever seen crossing there);
line of sight was not good from the left and, even from the right, it's possible Carlo or Cecilia could have started their crossing when the drivers were close because the warning time of approaching vehicles was short.
they would not be likely to cross with a group of pedestrians, and they would not be comfortable waiting with their foot in the street.
Factors that indicated the drivers would be likely to stop:
road conditions were good;
they'd be using a cane.
If they were hit, likelihood of being seriously injured or killed:about 62%
vehicles were going about 40 mph (see chart on page 5, or look at the bottom of the front page of your checklist)
Summary: Risk of being seriously injured or killed is very high.
If Carlo or Cecilia started to cross when it's quiet, it is likely they'd be surprised by an approaching vehicle that could reach them and if that happened, it is very likely that it would hit them and if it did, they'd have about a 62% chance of being seriously injured or killed.
Is the risk acceptable?
Carlo and Cecilia both felt that the risk of crossing in that situation was definitely NOT acceptable.
Feasible alternatives if the risk of crossing was not acceptable:
Look for another location with better control or where they are more visible to the drivers and they can hear the approaching vehicles with more warning, or where drivers expect more pedestrians.
Figure some way to avoid the crossing, such as getting a ride.
Request environmental modifications adding bulbouts and a refuge island to change the 4-lane crossing into two one-lane crossings, like the first example on page 12.
QUESTION: Does this meet the conditions to be able to use the alternative of being prepared to turn around and return to the curb?
(Click here for the answer)
Scenario #3: Main Street, Annapolis
WARNING TIME OF APPROACHING VEHICLES:
It was not possible for Cecilia or Carlo to hear any of the approaching vehicles until they were just a few seconds away, and in some cases there was NO warning of the approaching vehicles because they couldn't be heard even when they were IN the crosswalk!
Note: Can you speculate why it was so hard to hear the vehicles?
Think about the residual sound level of "quiet" in most cities, and consider how much noise the vehicles would make when they are moving slowly (quiet cars may not even be audible at that speed).
Click here for a written description of the video.
ANALYSIS:
Would Cecilia and Carlo have the right of way at this crossing?
Yes -- The crosswalk was well marked, and in most states it would be considered a crosswalk even if it hadn't been marked.
Likelihood that they'd be surprised by an approaching vehicle if they started to cross when quiet:extremely likely
Reasoning: very high traffic volume (almost always a vehicle was approaching) and there was almost no warning of approaching vehicles (some passed by without being heard at all!)
If they were surprised, likelihood that the driver would hit them:extremely unlikely
Factors that indicated the drivers would not be likely to stop for Carlo or Cecilia:
there was more than one lane approaching so there was the possibility of "multiple threats;"
Factors that indicated the drivers would be likely to stop:
traffic is extremely slow;
pedestrians were highly expected (crosswalk was marked and many pedestrians crossed there);
Line of sight, visibility and road conditions were good;
They could safely stand with a foot in the street to wait to cross;
They'd be using a cane;
observation of the drivers demonstrated a high willingness to stop (pedestrians never had to wait for the drivers);
Note: Even though there were many groups of pedestrians crossing, Carlo and Cecilia didn't consider this a factor because they weren't sure they'd be in a group when they crossed.
If they were hit, likelihood of being seriously injured or killed:less than 20%
Vehicles were going about 5-10 mph, which put them in the chart's first category (see chart on page 5, or look at the bottom of the front page of your checklist).
That category included traffic moving as fast as 20 mph, so they figured the likelihood of being seriously injured or killed by these vehicles was less than the percentage indicated in the chart.
Summary: Risk of being seriously injured or killed is very low.
Although it is extremely likely that they would be surprised by a vehicle approaching the crosswalk which could reach them if they start to cross when it's quiet,
when that happens it is extremely unlikely that the vehicle would hit them and if it did, the chance that they'd be seriously injured or killed is less than 20%.
Is the risk acceptable?
Cecilia felt that the risk of crossing in that situation was acceptable, but Carlo did not.
It would be very likely that when he started the crossing, vehicles would be in the crosswalk or approaching it, and he didn't like crossing without being able to know what was happening around him.
Feasible alternatives if the risk of crossing was not acceptable:
get assistance (there are lots of pedestrians crossing who could help)
cross at another location where there is a traffic signal or where they can hear better:
As Main Street goes up the hill it becomes more narrow, and lanes are blocked for parking, as shown in the first picture to the right (taken from the middle of the crosswalk that was assessed).
A block away the street is half as wide and it is possible to hear traffic better (shown in the second photo), and at the top of the hill (about two blocks away) is a traffic signal.
Figure some way to avoid the crossing, such as getting a ride.
QUESTION: Does this meet the conditions to be able to use the alternative of being prepared to turn around and return to the curb?
(Click here for the answer.)
Reflections:
These situations were chosen because they presented so much variety! No two situations had the same features:
Situation 1 was the only one where the likelihood of being surprised by an approaching vehicle was low;
Situation 2 was the only one where the likelihood that drivers would yield was low; and
Situation 3 was the only one where the likelihood was low that if you were hit, you'd be seriously injured or killed.
Were you surprised that the situation that had the least warning of approaching vehicles was not the one with the highest risk?
No single factor can predict whether or not the risk will be high -- to analyze situations, we need to look at and weigh all the factors.
If you'd like to process what you've learned about analyzing risks, making decisions and considering alternatives by applying it to real situations, this page is for you!
If not, feel free to move to the next page -- you can always come back later and play.
