I think perhaps it worked as intended right? The goal seems to be to keep traffic free flowing in the lane.

> Tolls for the Express Lanes are dynamic, meaning they change periodically based on real-time traffic conditions to keep the Lanes free-flowing.

> However, rates may rise significantly above the typical range for periods of time in the event of unusually heavy congestion or a specific event like a traffic accident or lane(s) closure.

So because the trucks were slowing things down the price raised deterring more vehicles from entering and slowing this down more. It makes sense to me. ¯\_(ツ)_/¯

Maybe I misread this but my understanding is that the algorithm is intended to have all lanes have the same flow rate. If one lane is slow, charge more on that lane to incentivize people to use the other lanes instead. If all lanes are flowing equally, they will be priced (mostly) equally.

In this case, the slowness was based on weather conditions and plow trucks not because all the traffic was on express lane and all other lanes were empty. Clearly, their algorithm needs to take road conditions into account when creating this prices.

I didn't read this as a premium to use the express lane or only allow rich people to get home, just an unintended consequence of a beneficial program finding an edge case.

There aren't separate charges for separate lanes. There's a set of express lanes, which get a dynamic per-mile charge based on conditions, and a set of normal freeway lanes which cost nothing.

The intent is to set the express lane pricing to a level that keeps their speed at 45MPH or more. The free lanes just do whatever.

So the problem here is more of a faulty algorithm?

Less a "faulty algorithm" and more a moral hazard. The intent of the rules is to limit usage during periods of congestion not caused by the road operators themselves. The distinction is that human actors are not moral-free mechanisms.

You wouldn't know, you'd have to audit the algorithm to reveal the details.

Honestly, I only saw a few flurries. I think everyone saw that and hopped on the express lanes. The day before a little rain fell and there were accidents everywhere. Guessing it was fresh on our collective minds.

I passed a lot of cars in the express lanes on my way home. Cringing at the though of what car accidents lay ahead, but everything was clear.

Arguably though, if the capacity of the road is reduced, then charging more for what remains is supply and demand, right?

In that case, one could charge $100 right? The capacity of the road is reduced then as well.

No, I'm not saying the price increase is reducing capacity. I'm saying the trucks are reducing capacity (i.e. supply) and so the price is rising in response.

> I'm saying the trucks are reducing capacity (i.e. supply)

Source?

The comment I was originally replying to?

>> the company (said) two salt and plow trucks were working on the southbound Express Lanes on I-495 and I-95, causing traffic to slow

Now, I go back to my original question : Why is $30 the price that will do so? It could be $5 or $100.

Well I don't know exactly how their algorithm works, but I'd guess they keep track of average travel times by scanning licence plates, and then raise prices when they go below the target speed, and lower them again when speeds increase?

Unfortunately, "guesses" and "algorithms" built by humans are not good enough. The larger point is again the same - you can post hoc rationalize ANY price with that argument.

Well, we can measure efficacy here by seeing how far average speeds differ from the target speed over time. If they match closely, then I think it's reasonable to say it is "good enough".

This is not ONLY about speed. There are two variables here - speed and price. You've got to tell me the point at which you get the best speed at the best price.

>You've got to tell me the point at which you get the best speed at the best price.

What does that even mean?

People value speed differently, and so are being charged differently. If people value speed highly enough, they can pay for the express lane, and if they don't they can take a presumably slower non-express lane. Making this distinction allows everyone to get closer to their own individual "best speed at the best price".

It means that $30 may or may not be the optimal price. People may value the same facility at $1 or $100. The onus is on the entity who justifies the price to prove that $30 is indeed the best price point. At this moment, I've seen no justification for the $30 price point.

Optimal in what sense?

Right, traffic density increased without a corresponding increase in throughput.