I have some actual moral qualms about typing this out. I'll try to make it as short as possible.

Will blocking a single bridge help? Nope. The whole "raising awareness" and "starting a conversation" are irrelevant, for the most part.

So, let's say you live in America and want to effect meaningful change. In order to do so, you want to get the attention of the politicians and the media.

I should probably title this, "How to get the FBI Party Van Parked on Your Street."

However, unless they really stretch the laws, this is probably perfectly legal. I'll leave the morality judgment up to you, the reader, and simply tell you how to do this.

Some history:

I modeled traffic. This doesn't actually come in handy very often, but sometimes it does. Of course, when all you have is a hammer, every problem looks like a nail.

I like to say that I built the greatest traffic simulation game ever made. Of course, I'm biased. Eventually, we'd even be able to output some of that simulation as graphical representations, but that's a story for another day.

Traffic modeling concerns itself with optimizing - it's not always optimizing the greatest throughput. Sometimes, it's optimizing for speed, simplicity, or efficiency.

In order to understand traffic, it helps to realize that traffic is a chaotic system. A chaotic system is a system that appears to have random elements but, with enough data, you can tease out certain patterns. This is all very complicated and has varied accuracy depending on your ability to know the initial starting state.

However, with enough information, you can bring any city's traffic to a crawl with minimal effort. Give me a month to study the data (well, longer now as I'm retired and don't have the hardware to hand, the code, or current models) and some two way radios.

After I've studied the data, give me a dozen drivers and I can almost certainly reduce throughput by greater than 50% - and that's without breaking any laws or being the direct cause of an accident. It's really not hard. Start ahead of time and coordinate to merge slowly, to move at the posted speed limit in specific areas, to change lanes and brake, and to do this at key points where you can create bottlenecks.

I only say I can do it. To be completely frank about it, I've never yet met a municipality that would consider allowing me to actually try this. However, I can replicate this time and time again - and I have reasons to believe this would be as effective as it is in the models.

It won't even take much to do so. A dozen cars may actually be overkill, depending on the infrastructure. You can actually (I don't recommend doing so) test and see the results of some of the methods.

Find a spot in traffic where there is room in front of you. Speed up slowly until you're exceeding the speed of the vehicle in front of you. Brake late and hard. For bonus points, change lanes as you brake.

What will happen is the people behind you will increase their speed and will still be adapting to your speed increases. When you brake, they'll need to brake harder because they braked later due to reaction times. This will increase and ripple its way back through traffic - you can actually watch it happen. If done "right," it will spill over into the other travel lanes.

All you had to do was be the butterfly and you've now sent a cascading wave of confusion and reaction behind you. Not only will the person behind you have to brake harder, the people behind them will have to do so and, depending on their distances between cars, will have to keep on doing so for many cars behind you.

This also gets compounded by people being unable to see the first braking car(s). They are unable to see the cars way ahead in the line and they begin acting in what they believe is a rational manner. They brake hard and seek to change lanes.

(If you want to stop the ripple, brake and leave space between you and the vehicle in front of you - and allow people to safely merge into that space while making room to maintain that space in front of you. One car can significantly impact throughput.)

Why do I type all this?

Well, imagine you had a government that you felt was a tyranny. Imagine you had a bunch of people who agreed with you?

See, it's VERY important that you have a bunch of people who agree with you - otherwise, you're just an asshole. This way, you're an asshole with a legitimate democratic complaint. And, trust me, you are an asshole if you do this.

Let's assume that you're right in your presumptions about how people feel concerning the political arena. Let's just say you get 100,000 people who agree with you.

If you can't get 100,000 people who agree with you - and want to effect change - perhaps you're message really isn't important?

Now, pick a day... Go on, pick one. I recommend picking a day that is a Friday. I'd specifically recommend that you pick a Friday that marks the end of a week-long legislative session.

So, you have a date and 100,000 people.

Now, you need a time and a place. I'd suggest 12:00 noon and 1600 Pennsylvania Avenue.

Not to worry, you're not getting there.

Those 100,000 people will then set their GPS to arrive at 1600 Penn. Ave and they'll set it to arrive at the same time.

From across the country, people will leave and head to that address. They'll leave at different times because their goal is not the same departure time - but the same arrival time. Their goal is to all arrive at 1600 Penn. Ave at noon.

Of course, they can't do this. No, no... The urban area simply can't adapt to that much traffic all arriving at the same time and trying to get to the same place.

So, eventually you're going to reach a point where your car can go no further. If you're the first to arrive at 1600 Penn. Ave, just stop your car. (Impeding the flow of traffic is a minor offense, not subjecting one to jail time.)

Everyone else, when you get as close as you can, do the same thing. Stop your vehicle, exit your vehicle, lock the doors, and go have a drink.

Plan on being there for a while. You might want to bring food, water, blankets, prescription medication, camping gear, and be prepared to wait for a long while.

This will cause a giant wave of congestion that brings traffic to a halt - not just in DC but in the wider area. I once did the math, based on just 100,000 participants and current populations and existing local traffic, and my estimate was that it would create a snarl of traffic that's about 50 miles across - covering all primary, secondary, and tertiary travel lanes.

Here's the fun part... You've locked your vehicle and exited it. You've simply walked away. (Other than the first few people, this is a reasonable choice after a period of time.) They also won't be able to sort all the vehicles from those who were there to intentionally cause mayhem and those who were there for more "legitimate" (subjective) reasons.

They will be weeks moving these vehicles. They will be calling in tow trucks from around the country. They will initially clear single lanes for emergency traffic and this process is almost certainly not going to be gentle on your car. They'll be bringing in the National Guard and yanking your vehicle out of the way with chains.

And they haven't got anywhere to park that many additional cars. You're not just going to have 100,000 cars - you are going to have many of the local cars caught in it as well. You're going to have delivery vehicles, giant trucks, people towing trailers, and all that sort of stuff. You'll have RVs and limousines, people towing ATVs on their way out to the country for the weekend, taxis, police cars, etc...

This will shut down vehicular traffic for quite a while. Not only that, it will slow it down for even longer.

This affords you plenty of time to talk to the media and you'll absolutely have attention from the politicians.

Caveats: This is VERY severe. This will hamper emergency responses. This will negatively impact people who are innocent. This will seriously mess things up - probably for weeks.

Do NOT do this unless you're damned certain you're right. Do NOT do this unless you're able to accept that people will be harmed. This is very, very likely to result in indirect deaths.

So, blocking one bridge isn't very effective. However, blocking a lot of them, all at once, almost certainly will get attention. (Depending on your cause, the attention may be negative or positive.) Blocking one bridge isn't going to do much attention getting. Shutting a city down for multiple days and slowing it down for weeks, on the other hand, probably will.

I'd like to stress, again, that this isn't something to be taken lightly. It's a near certainty that multiple people will suffer because of this. However, if your choice is this or violent revolution... This is very, very much a "second to last choice option."

Finally, I'm sort of sorry for the length. However, I figured I would try to explain it in full AND stress that it's a horrible idea - but almost certain to get attention. What you do with that attention is up to you, but it's going to get attention. I am ABSOLUTELY not suggesting you do this, at least not at this time.