道路幅員減少アイルランド

わかりやすい説明と視覚的な例を使った図解付きの本で、交通ルールをシンプルかつ楽しく学べます。


17. 道路幅員減少

道路幅員減少は、前方で車道または利用可能な通行幅が狭くなることを示します。工事、橋、障害物、車線減少、道路構造の変化などが原因です。

運転者は減速し、車線位置を調整し、対向車や隣接車線に注意する必要があります。どちら側が優先か、合流方法が指定されているかは標識や現地規則に従います。

道路幅員減少
What is a road narrowing?

A road narrowing is a section where the usable width of the road becomes smaller. Traffic may have less space to pass, merge or travel beside other road users.

How can you recognise a road narrowing?

It may be indicated by a triangular warning sign showing the road edges moving closer together. The symbol may show narrowing on both sides, the left side or the right side.

What can cause a road to narrow?

A road may narrow because of a bridge, tunnel, barrier, traffic-calming measure, roadworks, parked vehicles, landslide, damaged road edge or reduction in the number of lanes.

Does a narrowing sign impose a speed limit?

No. It normally warns of danger rather than setting a numerical speed limit. Drivers must still reduce speed when necessary to pass safely.

Does a narrowing sign determine who has priority?

Not by itself. Priority may be established by separate signs, signals or local rules. Without them, drivers should approach cautiously and cooperate.

Who has priority when the obstruction is on one side?

In many countries, the driver whose side is obstructed must give way to approaching traffic. The precise rule depends on local law and any priority signs displayed.

What if the road narrows equally from both sides?

Neither direction necessarily has automatic priority. Drivers should reduce speed, assess who can pass safely and avoid entering when doing so would block approaching traffic.

What do priority signs at a narrow section mean?

One sign may require you to give way to oncoming traffic, while the corresponding sign may indicate that you have priority. Drivers must still avoid entering when the passage is already occupied or blocked.

Does having priority mean you must continue?

No. Priority is not an obligation to proceed. Slow down or stop when another vehicle is already in the narrow section or when continuing would create danger.

What should you do when another vehicle is already in the narrowing?

Allow it enough room to leave the narrow section. Do not enter if the available width is insufficient for both vehicles to pass safely.

How should you approach a road narrowing?

Check mirrors, reduce speed smoothly and observe oncoming traffic, cyclists, pedestrians and vehicles beside you. Be prepared to stop or merge.

Must you use an indicator when the road narrows?

Use an indicator when you must change lanes or move laterally. Merely following a lane that bends with the road may not require a signal under local law.

What should you do when your lane ends?

Check the adjacent lane, signal and merge safely according to the local merging rules. Do not force another driver to brake or leave the road.

What is zipper merging?

Zipper merging means that vehicles from an ending or blocked lane merge alternately with vehicles in the continuing lane, usually immediately before the narrowing during congestion.

Should you merge early during heavy congestion?

Where zipper merging applies, continue using both lanes and merge alternately near the narrowing. In free-flowing traffic, change lanes safely when a suitable gap is available.

May you overtake near a road narrowing?

A narrowing sign does not always prohibit overtaking, but overtaking should be avoided when there is insufficient width, visibility or distance to complete the manoeuvre safely.

How should you pass cyclists at a narrowing?

Wait behind the cyclist when the required passing distance cannot be maintained. Do not squeeze past or force the cyclist towards a kerb, barrier or damaged road edge.

How should large vehicles use a narrow section?

Large vehicles may need additional width and may cross lane or centre markings where legally permitted. Other drivers should leave sufficient space and avoid passing alongside them in the narrowing.

May pedestrians be present at a road narrowing?

Yes. Pavements or verges may also become narrow or blocked. Drivers should expect pedestrians or wheelchair users to enter the carriageway to pass an obstruction.

May you stop or park in a road narrowing?

Only where it is permitted and enough width remains for traffic to pass safely. Never stop or park where the vehicle would create danger, obstruct visibility or prevent other vehicles from passing.

What should you do at a temporary roadworks narrowing?

Follow temporary signs, signals, barriers and instructions from authorised workers. Temporary traffic controls may replace the normal priority or lane arrangement.

What should you do in poor visibility?

Reduce speed further, increase the following distance and be prepared for a stopped vehicle beyond the narrowing. Use the required lights without dazzling approaching road users.

1 アイルランド 2 高速道路 3 住宅地域 4 ゾーン 5 速度制限 6 自転車道 7 歩行者注意 8 橋 9 速度抑制ハンプ 10 有料道路 11 岸壁 12 勾配 13 バス専用レーン 14 一時停止標識 15 譲れ 16 ラウンドアバウト 17 道路幅員減少 18 横断歩道 19 踏切 20 右左折禁止 21 学校周辺 22 動物横断 23 滑りやすい道路 24 カーブ 25 シェブロン標識 26 逆走 27 高さ制限 28 重量制限 29 速度取締表示 30 次の交差点で優先 31 信号機あり警戒 32 歩行者信号 33 左側通行 34 運転免許証 35 規制解除 36 駐車 37 駐車禁止 38 後退 39 Uターン 40 ホステル 41 観光地 42 ナンバープレート 43 一般危険 44 自転車利用者 45 バス 46 警察 47 救急車 48 タクシー 49 欧州排出ガス基準 50 ポットホール 51 通路 52 粒子状物質 53 大気汚染 54 ラッシュアワー 55 交通法規 56 2+2道路 57 道路側溝 58 カーゴバイク 59 林業車両 60 建設車両 61 セミトレーラートラック 62 トロリーバス 63 スピードペデレック 64 配送車両 65 アイドリング 66 レッカー車 67 四輪駆動 68 自転車 69 オートバイ装備 70 トラム 71 軌道 72 キャラバン 73 トレーラー 74 牽引ヒッチ 75 消防車 76 サイレン 77 車列 78 緊急車両の警光灯 79 農業機械 80 電動自転車 81 電気自動車 82 ペデレック 83 クアドリシクル 84 マイクロカー 85 全地形対応車 86 バン 87 キャンピング車 88 スクーター 89 Trikke 90 パーソナルモビリティ 91 スケートボード 92 セグウェイ 93 キックスクーター 94 ローラースケート 95 郵便配達員 96 ヒッチハイカー 97 幼児 98 子ども 99 障害 100 カートレイン ...