Если я выйду поздно, я снова попаду в пробку по дороге на работу.

This is a very common difference between English and Russian.

In Russian, when you are talking about a real future condition, you normally use the future in both parts:

• Если я выйду поздно, я попаду в пробку.

Literally, that is closer to:

• If I leave late, I will get into traffic.

But grammatically, Russian uses future forms in both clauses.

So:

• если я выйду = if I leave / if I go out
• я попаду = I will get into

English avoids will after if in this kind of sentence, but Russian does not.

Because they are forms of perfective verbs.

In Russian:

• imperfective verbs form a true present tense
• perfective verbs do not have a present meaning; their “present-looking” forms actually refer to the future

So:

• выходить → imperfective → я выхожу = I am leaving / I leave
• выйти → perfective → я выйду = I will leave

And:

• попадать → imperfective
• попасть → perfective → я попаду = I will get into / I will end up in

So even though выйду and попаду use endings that resemble present-tense endings, they are future in meaning because the verbs are perfective.

Because the sentence is about a single completed action in the future: leaving late on one occasion.

• выйду = perfective, one completed departure in the future
• выхожу = imperfective present, I am leaving / I leave

Compare:

• Если я выйду поздно... = If I leave late...
• Когда я выхожу поздно, я попадаю в пробку. = When I leave late, I get stuck in traffic.
  This describes something habitual or repeated.

So выйду is used because this sentence is about a particular future situation, not a general habit.

Here выйти means to leave / to head out / to set out.

Literally, выйти often means to go out or to come out, but in everyday Russian it is also very commonly used for leaving home, leaving a building, or setting off somewhere.

So in this sentence:

• Если я выйду поздно... = If I leave late...

A more literal image is if I go out late, but natural English here is if I leave late.

Yes, it is a very common expression.

• попасть в пробку = to get into a traffic jam / to get stuck in traffic

Word by word:

• попасть = to get into, to end up in
• пробка = literally cork, but also traffic jam

So:

• я попаду в пробку = I’ll get into a traffic jam

You may also hear:

• застрять в пробке = to get stuck in a traffic jam

Both are common, but попасть в пробку emphasizes ending up in the jam, while застрять в пробке emphasizes being stuck there.

Because попасть в normally takes the accusative when it means to get into something.

So:

• пробка → accusative singular = пробку
• попасть в пробку = to get into a traffic jam

Compare the two cases:

• в пробку = into the traffic jam → direction/result → accusative
• в пробке = in the traffic jam → location/state → prepositional

Examples:

• Я попал в пробку. = I got into a traffic jam.
• Я сейчас в пробке. = I’m in a traffic jam right now.

This phrase has two different parts:

1. по дороге

This means on the way or literally along the road/route.

After по, Russian often uses the dative case.

• дорога → dative singular = дороге
• по дороге = on the way / along the road

2. на работу

This means to work.

Here на shows direction toward a destination, so it takes the accusative:

• работа → accusative singular = работу
• на работу = to work

So the whole phrase:

• по дороге на работу = on the way to work

This is a very common expression.

Compare:

• Я еду на работу. = I’m going to work.
• Я уже на работе. = I’m already at work.

Because поздно is an adverb, and it modifies the verb выйду.

• поздно = late
• поздний / поздняя / позднее = late, but as an adjective

Here we need an adverb because we are describing how / when the person leaves:

• выйду поздно = leave late

If you used an adjective, it would have to describe a noun:

• поздний поезд = a late train
• поздняя встреча = a late meeting

So поздно is the correct form here.

Снова means again.

In this sentence:

• я снова попаду в пробку = I’ll get into traffic again

Its position is fairly flexible, though some placements sound more natural than others. For example:

• Я снова попаду в пробку. = I’ll again get into traffic.
• Я попаду в пробку снова. = I’ll get into traffic again.
  This is also possible, but often gives a bit more emphasis to again.

Usually снова goes before the verb or before the part you want to emphasize.

You can also use опять, which often means the same thing in everyday speech:

• Если я выйду поздно, я опять попаду в пробку.

Yes, you could. Russian word order is flexible.

Both are natural:

• Если я выйду поздно, я снова попаду в пробку.
• Если я поздно выйду, я снова попаду в пробку.

The difference is mostly about emphasis and rhythm, not basic meaning.

• выйду поздно is a neutral, very natural order
• поздно выйду may put a little more focus on late

Russian often uses word order to highlight what is important, but in a sentence like this, both versions are acceptable.

Sometimes yes, but выйду is the most straightforward choice here.

• выйти often means to go out / leave (a place)
• уйти often means to go away / leave with a slightly stronger sense of departure or being gone

In many real contexts, both can work:

• Если я выйду поздно...
• Если я уйду поздно...

But выйду sounds very natural when talking about setting out from home or leaving in order to go somewhere. It fits well with commuting.

So a learner should understand уйду, but выйду is probably the safest and most idiomatic choice in this sentence.

As written, it most naturally refers to a specific future situation:

• If I leave late, I’ll get stuck in traffic again.

That is because both verbs are perfective future:

• выйду
• попаду

If you wanted to describe a general repeated fact, Russian would more naturally use imperfective forms:

• Если я выхожу поздно, я снова попадаю в пробку по дороге на работу.
• Когда я выхожу поздно, я попадаю в пробку.

So the original sentence sounds like a prediction about what will happen on a particular occasion or in a future situation.